16-CHANNEL CONSTANT CURRENT LED DRIVER WITH

Transcription

1 Version : PRE. Issue Dae : 28/7/3 File Name Toal Pages : 3 : SP--PRE..doc 6-CHANNEL CONSTANT CURRENT LED DRIVER WITH 6-bi PROGRAMMABLE PWM OUTPUTS 9-7F-, Prosperiy Road I, Science Based Indusrial Park, Hsin-Chu, Taiwan 3, R.O.C.

2 6-CHANNEL CONSTANT CURRENT LED DRIVER WITH 6-bi PROGRAMMABLE PWM OUTPUTS General Descripion is a 6-channel consan curren sink LED driver. Each channel has independen 6-bis (65536 seps) grayscale PWM conrol curren oupus. I incorporaes shif regisers, daa laches, consan curren circuiry wih curren value se by an exernal resisor, and buil-in LED open deecion circui o deec error saus. I combines he selecions wih rising / falling edge serial ou, auo-reload/one-sho PWM oupu, inernal/exernal grayscale clock source. I is specifically designed for LED display or lighing applicaions. Feaures Consan-curren oupus: 5mA o 6mA adjusable by one exernal resisor 6-bi linear PWM conrol curren oupus for each channel Maximum oupu volage: 7V Maximum clock frequency: 25MHz Auo-Reload / One-Sho Mode selecion. Serial ou clock edge selecion Rising / Falling edge selecion Inernal / Exernal PWM clock mode selecion Buil-in real-ime open deecion Package and pin assignmen compaible o convenional LED drivers (DM34/5/6, DM3C) Power supply volage: 3.3V o 5V Schmi Trigger inpu Oupu channel delay Applicaions Indoor/Oudoor LED Video Display LED Variable Message Signs (VMS) Sysem LED Decoraive Lighing Package Types DIP24B, SOP24B, SSOP24, TSSOP24E (wih exposed pad) 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page

3 Block Diagram OUT OUT OUT 5 VCC LED Open Deecor () LED Open Deecor () LED Open Deecor (5) GND Inernal Oscillaor Consan Curren Driver () Consan Curren Driver () Consan Curren Driver (5) REXT 6-bi Couner 6-bi PWM Generaor () 6-bi PWM Generaor () 6-bi PWM Generaor (5) LAT 6-bi Lach Regiser () 6-bi Lach Regiser () 6-bi Lach Regiser (5) DAI 6-bi Shif Regiser () 6-bi Shif Regiser () 6-bi Shif Regiser (5) DAO 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 2

4 Pin Connecion GND DAI LAT OUT OUT OUT2 OUT3 OUT4 OUT5 OUT6 OUT DIP24B SOP24 SOP24B TSSOP24E ( op view ) VCC REXT DAO OUT 5 OUT 4 OUT 3 OUT 2 OUT OUT OUT 9 OUT 8 Pin Descripion PIN No. PIN NAME FUNCTION SOP24B/SSOP24/TSSOP24E: TSSOP24E: exposed pad GND Ground erminal. SOP24B/SSOP24/TSSOP24E: 2 DAI Serial daa inpu erminal. SOP24B/SSOP24/TSSOP24E: 3 SOP24B/SSOP24/TSSOP24E: 4 LAT Synchronous clock inpu erminal for serial daa ransfer. Daa is sampled a he rising edge of. Inpu erminal of daa srobe: H means daa on shif regiser goes hrough lach (level rigger), all oupus off and couner rese immediaely L means daa is lached. SOP24B/SSOP24/TSSOP24E: 5~2 OUT~5 Sink consan-curren oupus (open-drain). SOP24B/SSOP24/TSSOP24E: 2 SOP24B/SSOP24/TSSOP24E: 22 SOP24B/SSOP24/TSSOP24E: 23 DAO REXT Gray Scale Clock () : Inpu erminal for PWM operaion. Serial daa oupu erminal. Daa shif ou a he rising edge of in REM (defaul), or daa shif ou a he falling edge of in FEM 2. Exernal resisors conneced beween REXT and GND for oupu curren value seing. SOP24B/SSOP24/TSSOP24E: 24 VCC Supply volage erminal. Rising Edge Mode 2 Falling Edge Mode 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 3

5 Equivalen Circui of Inpus and Oupus., DAI, LAT, erminals 2. DAO erminals PCB Layou Consideraion To connec an exernal resisor o REXT pin and ground can deermine he maximum oupu curren. If here is any disurbance occurred o REXT pin, he consan curren oupu may be unsable or has noise happened. Since REXT (pin23), DAO (pin22), and (pin2) are nex o each oher, he mos possible inerference is caused by DAO or signal. Accordingly, i is recommended ha adding some shielding area wihin he above pins in PCB layou, or laying he signal line of above pins on differen PCB layer will preven he noise problems effecively. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 4

6 Maximum Raings (Ta=25 C, Tj(max) = 5 C) CHARACTERISTIC SYMBOL RATING UNIT Supply Volage VCC -.3 ~ 7. V Inpu Volage VIN -.3 ~ VCC+.3 V Oupu Curren IOUT 7 ma Oupu Volage VOUT -.3 ~ 7 V Inpu Clock Frequency F 25 MHz GND Terminal Curren IGND 2 ma Power Dissipaion (4 layer PCB, a Ta=25 ) Thermal Resisance (4 layer PCB, a Ta=25 ) PD Rh(j-a) 4.7 ( TSSOP24E exposed pad) 2.9 ( SOP24B).87 (DIP24B).79 ( SSOP24 ) 3 ( TSSOP24E exposed pad) 57 (SOP24B) 67 (DIP24B) 7 (SSOP24 ) Operaing Temperaure Top -4 ~ 85 C Sorage Temperaure Tsg -55 ~ 5 C W C/W Recommended Operaing Condiion CHARACTERISTIC SYMBOL CONDITION MIN. TYP. MAX. UNIT Supply Volage VCC V Oupu Volage VOUT Driver On *..5VCC Oupu Volage VOUT Driver Off *2 7 IO OUTn 5 6 Oupu Curren IOH VOH = VCC.4 V +.5 IOL VOL =.2 V -.5 Inpu Volage VIH.8VCC VCC VCC = 3.3 V ~ 5.5V VIL..2VCC Inpu Clock Frequency F Single Chip Operaion 25 Inpu PWM Frequency F 3.3V~5.5V 25 LAT Pulse Widh w LAT 5 Pulse Widh w 5 Se-up Time for DAI seup(d) VCC = 5.V Hold Time for DAI hold(d) Se-up Time for LAT seup(l) Hold Time for LAT hold(l) 36 *3 V ma V MHz ns * Noice ha he power dissipaion is limied o is package and ambien emperaure. *2 The driver oupu volage including any overshoo sress has o be complian wih he maximum volage (7V). *3 Due o open deecion operaion and oupu channel delay consideraion. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 5

7 Elecrical Characerisics (VCC = 5. V, Ta = 25 C unless oherwise noed) CHARACTERISTIC SYMBOL CONDITION MIN. TYP. MAX. UNIT Oupu Leakage Curren IOL VOH = 7 V ±. ua Oupu Volage (S-OUT) VOL IOL =.25 ma.4 VOH IOH=.4 ma VCC-.2 V Oupu Curren Skew (Channel-o-Channel) * IOL ±3 % VOUT =. V Rrex = 2.2 KΩ Oupu Curren Skew (Chip-o-Chip) *2 IOL2 TBD TBD TBD ma Oupu Volage Regulaion % / VOUT Rrex = 2.2 KΩ VOUT = V ~ 3 V ±. ±.5 % / V Supply Volage Regulaion % / VCC Rrex = 2.2 KΩ ± ±4 LED Open Deecion Threshold V(od) all oupus urn on.2 V I DD(off) power on all pins are open unless VCC and GND (inernal mode 5.5 Supply Curren *3 I DD(off) I DD(on) I DD(on) I DD(on) power on all pins are open unless VCC and GND (exernal mode) inpu signal is saic Rrex = 2.4 KΩ all oupus urn off inpu signal is saic Rrex = 2.2 KΩ all oupus urn off inpu signal is saic Rrex = 57 Ω all oupus urn off ma * Channel-o-channel skew is defined as he raio beween (any Iou average Iou) and average Iou, where average Iou = (Imax + Imin) / 2. *2 Chip-o-Chip skew is defined as he range ino which any oupu curren of any IC falls. *3 IO excluded. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 6

8 Elecrical Characerisics (VCC = 3.3 V, Ta = 25 C unless oherwise noed) CHARACTERISTIC SYMBOL CONDITION MIN. TYP. MAX. UNIT Oupu Leakage Curren IOL VOH = 7 V ua Oupu Volage (S-OUT) VOL IOL =.25 ma.4 VOH IOH=.4 ma VCC-.2 V Oupu Curren Skew (Channel-o-Channel) * IOL ±3 % VOUT =. V Rrex = 2.2 KΩ Oupu Curren Skew (Chip-o-Chip) *2 IOL2 TBD TBD TBD ma Oupu Volage Regulaion % / VOUT Rrex = 2.2 KΩ VOUT = V ~ 3 V ±. ±.5 % / V Supply Volage Regulaion % / VCC Rrex = 2.2 KΩ ± ±4 LED Open Deecion Threshold V(od) all oupus urn on.2 V I DD(off) power on all pins are open unless VCC and GND (inernal mode) 4.5 Supply Curren *3 I DD(off) I DD(on) I DD(on) I DD(on) power on all pins are open unless VCC and GND (exernal mode) inpu signal is saic Rrex = 2.4 KΩ all oupus urn off inpu signal is saic Rrex = 2.2 KΩ all oupus urn off inpu signal is saic Rrex = 57 Ω all oupus urn off ma * Channel-o-channel skew is defined as he raio beween (any Iou average Iou) and average Iou, where average Iou = (Imax + Imin) / 2. *2 Chip-o-Chip skew is defined as he range ino which any oupu curren of any IC falls. *3 IO excluded. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 7

9 Swiching Characerisics (VCC = 5.V, Ta = 25 C unless oherwise noed) CHARACTERISTIC SYMBOL CONDITION MIN. TYP. MAX. UNIT Propagaion Delay ( L o H ) Propagaion Delay ( H o L ) -o-out 45.7 (rising edge)-o-dao plh VIH = VCC 36 (falling edge)-o-dao VIL = GND 6 -o-out Rrex = 2.2 KΩ 23.8 (rising edge)-o-dao phl 28 (falling edge)-o-dao VL = 5. V 4 Oupu Curren Rise Time or CL = 3 pf 8 Oupu Curren Fall Time of 7. Oupu Delay Time Uni Td 2 ns Swiching Characerisics (VCC = 3.3V, Ta = 25 C unless oherwise noed) CHARACTERISTIC SYMBOL CONDITION MIN. TYP. MAX. UNIT Propagaion Delay -o-out 48.8 (rising edge)-o-dao plh VIH = VCC 23 ( L o H ) (falling edge)-o-dao VIL = GND 23 Propagaion Delay -o-out Rrex = 2.2 KΩ 29.6 (rising edge)-o-dao phl 2 ( H o L ) (falling edge)-o-dao VL = 3.3 V 2 Oupu Curren Rise Time or CL = 3 pf 2 Oupu Curren Fall Time of 8.3 ns Oupu Delay Time Uni Td 3 VL VCC A CL CL CL CL DAI LAT OUTn REXT DAO GND CL Rrex Swiching Characerisics Tes Circui 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 8

10 Consan-Curren Oupu Consan-curren value (Iou * ) of each oupu channel is se by an exernal resisor conneced beween he REXT pin and GND. The curren scale ranging can be adjused from 5mA o 6mA by varying he resisor value. The reference volage of REXT erminal (Vrex) is approximaely.23v. The oupu curren value is calculaed by he foling equaion: Iou(mA) M Oupu curren as a funcion of Rex value Iou (ma) ~ Vrex (V) Rrex (KΩ) M Iou(mA) Rex Oupu Curren as a funcion of Oupu Volage Iou(A) Vou(V) In order o obain a good performance of consan-curren oupu, a suiable oupu volage is necessary. Users can ge relaed informaion abou he minimum oupu volage above. * Iou is ypical curren value seing under % PWM duy cycle. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 9

11 Serial Daa Inerface The serial-in daa (DAI) daa will be clocked ino 6 6 bi shif regisers synchronized on he rising edge of he clock (). The daa will be ransferred ino he 6 6 bi lach regisers when he srobe signal ( LAT ) is kep a level (level rigger); Oherwise, he daa will be held. The lach pulse should be sen afer he falling edge of he las clock wihin one frame daa. The serial-ou daa (DAO) will be shifed ou on synchronizaion of he clock (). Inpu Daa clock-in sequence The sequence of he grayscale PWM luminous daa of a driver showed as foling diagram. The inpu daa sequence of inpu daa is from he MSB of OUT5 (D5 [5:]) o he LSB of OUT (D [5:]) by ime passing. Serial-ou Daa clock-ou sequence The daa serial ou from DAO include lached grayscale daa and he LSB of each oupu daa covered by deecion message (ERR) afer LAT pulse be acive. The serial ou sequence of he daa is from he MSB of OUT5 (D5 [5:]) o he LSB of OUT (D [5:]) by ime passing. shif ou firs OUT 5 D 5 [5] D 5 [4] D 5 [3] D 5 [2] D 5 [] D 5 [] D 5 [9] D 5 [8] D 5 [7] D 5 [6] D 5 [5] D 5 [4] D 5 [3] D 5 [2] D 5 [] ERR [5] MSB OUT 4 LSB D 4 [5] D 4 [4] D 4 [3] D 4 [2] D 4 [] D 4 [] D 4 [9] D 4 [8] D 4 [7] D 4 [6] D 4 [5] D 4 [4] D 4 [3] D 4 [2] D 4 [] ERR[4] MSB LSB OUT D [5] D [4] D [3] D [2] D [] D [] D [9] D [8] D [7] D [6] D [5] D [4] D [3] D [2] D [] ERR[] MSB LSB * ERR[5], ERR[4], EER[] are Error Message of LED Open Deecion. `'is normal, and `'is abnormal. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page

12 Rising/Falling Edge Mode selecion The luminous daa serial ou from DAO by daa clock () as foling waveform. In rising edge mode (REM), he daa serial ou by he rising edge of DAO D[255] D[254] D[253] ERR[] E[2 55] LAT Rising Edge Mode (REM) DAO serial ou by rising edge. In falling edge mode (FEM), he daa serial ou by he falling edge of DAO D[255] D[254] ERR[] E[2 55] LAT Falling Edge Mode (FEM) : DAO serial ou by falling edge. *D[255], D[254], D[], E[255] are clock-in daa in Shif daa regiser of driver 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page

13 The defaul mode is he Rising-Edge Mode (REM * ) afer power-on. Users could do mode selec beween REM and FEM *2 by foling iming sequence. The opion shows wo rising edge of lach pulses ( LAT ) when he daa-inpu clock () kep a level hen sending one rising edge of pulses when LAT kep a level. Then we can receive serial-ou daa from he daa-oupu signal (DAO) a falling edge of afer he falling edge of LAT. The opion 2 shows hree rising edge of LAT when kep a level hen sending wo rising edge of, while LAT kep level a he same ime. Afer he falling edge of LAT, we receive serial-ou daa from DAO a rising edge of (REM). Noice ha when inernal RESET a level, all he shif regisers in will be cleared (Kep a Low level). 2 X X X X LAT 2 LAT 2 3 RESET (inernal) Opion : Timing Combinaion o se up Falling-Edge Mode (FEM) RESET (inernal) Opion 2 : Timing Combinaion o se up Rising-Edge Mode (REM) Auo-Reload/One-Sho Mode selecion The Auo-Reload mode (ARM) in means oupus can repea he grayscale PWM cycle over and over. I can decrease he daa amoun grealy compare o non-pwm funcion driver operaed in grayscale PWM applicaion. LAT Couner rese ( inernal or exernal ) OUT (curren) Frame Daa B Frame Daa B on off Auo-Reload Mode (ARM). The One-Sho Mode in means each oupu shows one grayscale PWM cycle foling one lach pulse. The grayscale PWM cycle sars wih he falling edge of LAT signal. The firs pulse afer LAT increases he grayscale couner by one and swiches on all oupus wih grayscale value. I makes driver synchronous conrol easily. * REM swich o FEM iming diagram please refer o page 6. * 2 FEM swich o REM iming diagram please refer o page 7. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 2

14 LAT Couner rese ( inernal or exernal ) OUT (curren) Frame Daa B on off One-Sho Mode (OSM) The defaul mode is he Auo-Reload Mode (ARM * ) afer power-on. Users could do mode selec beween ARM and One-Sho Mode (OSM *2 ) by foling iming sequence. The gray scale clock signal () should keep a during his mode selecion process. The opion shows four rising edges of lach pulse ( LAT ) when he daa-inpu clock () kep a level hen hree rising edges of when LAT kep a level. Then sars OSM afer he falling edge of LAT. The opion 2 shows five rising edges of LAT when kep a level hen sending four rising edges of signal, while LAT signal kep level. Afer falling edge of LAT, swich o ARM. Noice ha when inernal RESET a level, all he shif regisers in will be cleared (Kep a Low level) X X X X LAT LAT RESET (inernal) Opion : Timing Combinaion o se up One-Sho Mode (OSM) RESET (inernal) Opion 2 : Timing Combinaion o se up Auo-Reload Mode (ARM) * ARM swich o OSM iming diagram please refer o page 8. *2 OSM swich o ARM iming diagram please refer o page 9. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 3

15 Inernal/Exernal Clock Mode selecion Grayscale luminous of each channel comes from comparisons of grayscale PWM luminous daa and grayscale couner value. In inernal-clock mode, provides build-in oscillaor for couner operaion. In exernal-clock mode, he clock source of couner is from conrol sysem hrough pin. The defaul mode is he Inernal-Clock Mode(ICM * ) afer power-on. Users could do mode selec beween ICM and Exernal-Clock Mode (ECM 2 ) by foling iming sequence. The opion shows four rising edges of lach pulses ( LAT ) when he daa clock () kep a level and he grayscale clock () kep a hen sending hree rising edges of when LAT and boh kep a level. Then we can inpu exernal gray scale clock from pin o operae grayscale PWM funcion afer he falling edge of LAT. The opion 2 shows five rising edges of LAT when kep a level and a level hen sending four rising edges of, while LAT and kep a level. Afer he falling edge of LAT, grayscale PWM funcion operaes by inernal gray scale clock generaor. Noice ha when inernal RESET a level, all he shif regisers in will be cleared (Kep a Low level) X X X X LAT LAT RESET (inernal) Opion : Timing Combinaion o se up Exernal-Clock Mode (ECM) RESET (inernal) Opion 2 : Timing Combinaion o se up Inernal-Clock Mode (ICM) LED Open Deecion provides a real ime monior of LED open deecion funcion wihou exra componens or circui design. I will be idenified as a LED open failure when he oupu is urned on bu he oupu volage is be.2v. The es resul of each channel will wrie o is corresponden shif regiser which is in LSB posiion (ERR[5], ERR[4],., ERR[]) while srobe signal is acive. User can refer o iming diagram on page. Deecing repor could be rerieved from serial-ou (DAO) daa. If he sysem reads back, ha indicaes LED is in normal saus. Bu if was rerieved hen LED open failure has occurred. In order o make sure LED open deecion funcion is in well operaing condiion, hold(l) *3 should larger hen 36n sec(yp) due o he build-in delay beween oupus. And i is recommended ha all he luminance daa wroe o during deecion. * ICM swich o ECM iming diagram please refer o page 2. 2 ECM swich o ICM iming diagram please refer o page 2 * 3 Hold ime beween LAT and, please refer o page 5. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 4

16 Timing Diagram. -DAI, DAO w w 5% 5% 5% 5% seup(d) hold(d) DAI 5% 5% DAO 5% 5% plh phl 2. -LAT 5% 5% seup(l) hold(l) LAT 5% 5% wlat 3. -OUT 5% 5% ON OUT 5% 5% OFF 4. Oupu Delay Time Uni (N=, 4, 8, 2) plh phl ON 5% OUT N OFF d ON OUT N+ OFF 5% d ON OUT N+2 5% OFF d ON OUT N+3 5% OFF 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 5

17 Timing Diagram (Rising-Edge Mode swich o Falling-Edge Mode) Grayscale daa clock-in period Mode swich period Grayscale daa clock-in period DAI J[2] J[] J[] Don'care Don'care L[255] L[254] L[] Don'care M[255] M[254] M[253] M[252] DAO * I [] ERR[]* 2 J[255] J[254] L [255] *5 L [254] L [253 ] L [252 ] Couner rese LAT *3 (exernal) (inernal) OUTn *4 (curren ) Fr ame Daa I Fr ame Daa J Fr ame Daa L Fr ame Daa L * REM, ARM, IGM is configered by defaul. They can swich o FEM, OSM, EGM accordingly. All regisers in wih be rese when any swich procees occur. *2 ERR[] is he error message of LED open deecion. *3 LAT is level rigger, no edge rigger. *4 Iou urn off when LAT is level,and urn on a he firs rising edge when LAT is level. *5 J[255],J[2],J[],J[],I[],I[],L[255].L[254], L[],M[255],M[254], are serial daa for. on off 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 6

18 Timing Diagram (Falling-Edge Mode swich o Rising-Edge Mode) Grayscale daa clock-in period Mode swich period Grayscale daa clock-in period DAI M[2] M[] M[] Don'care Don'care O[255] O[254] O[] Don'care P [255] P [254] P [253] P [252] DAO * L[2] L[] ERR[]* 2 M [255] M[254 ] N[253] O[255] O[254] O[253 ] O[252 ]*5 LAT *3 Couner rese (exernal) (inernal) OUTn *4 (curren ) Fr ame Daa L Frame Daa M Frame Daa O Frame Daa O * REM, ARM, IGM is configered by defaul. They can swich o FEM, OSM, EGM accordingly. All regisers in wih be rese when any swich procees occur. *2 ERR[] is he error message of LED open deecion. *3 LAT is level rigger, no edge rigger. *4 Iou urn off when LAT is level,and urn on a he firs rising edge when LAT is level. *5 M[255],M[254], M[],L[2],L[],O[255].O[254], O[],P[255],P[254], are serial daa for. on off 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 7

19 Timing Diagram (Auo-Reload Mode swich o One-Sho Mode) Grayscale daa clock-in period Mode swich period Grayscale daa clock-in period DAI D[] Don' care Don' care F[255 ] F[254] F[] Don'care G [255] G [254] G [253] DAO * D[255] D[2 54 ] D[2 53 ] D[2 52 ] F[25 5 ] *5 F [2 54 ] F [2 53 ] F [252 ] LAT *3 Couner rese Couner rese (exernal) (inernal) OUTn *4 (curren) Frame Daa C Frame Daa D Frame Daa D Frame Daa F * REM, ARM, IGM is configered by defaul. They can swich o FEM, OSM, EGM accordingly. All regisers in wih be rese when any swich procees occur. *2 ERR[] is he error message of LED open deecion. *3 LAT is level rigger, no edge rigger. *4 Iou urn off when LAT is level,and urn on a he firs rising edge when LAT is level. *5 D[255],D[254], D[],F[255],F[254],...F[],G[255],G[254], are serial daa for. Refresh Rae (Hz) = Inpu Frequency (Hz) Toal PWM resoluion (2 6 ) For example, if he refresh rae in display sysem is er han 6Hz, he inpu frequency mus be er han 4MHz. on off 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 8

20 Timing Diagram (One-Sho Mode swich o Auo-Reload Mode) Grayscale daa clock-in period Mode swich period Grayscale daa clock-in period DAI G[] G[] Don'care Don'care I [255] I [254] I [] Don'care J[255] J[254] * DAO * F[] ERR[]* 2 G[255] G[254 ] G[253 ] G[253] G[252] *5 I [255] I [254] LAT *3 (exernal) (inernal) OUTn *4 (curren ) Fr ame Daa F Fr ame Daa G Frame Daa I Frame Daa I * REM, ARM, IGM is configered by defaul. They can swich o FEM, OSM, EGM accordingly. All regisers in wih be rese when any swich procees occur. *2 ERR[] is he error message of LED open deecion. *3 LAT is level rigger, no edge rigger. *4 Iou urn off when LAT is level,and urn on a he firs rising edge when LAT is level. *5 F[],G[255],G[],G[],I[255],I[254],...I[],J[255],J[254], are serial daa for. on off 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 9

21 Timing Diagram (Inernal-Clock Mode swich o Exernal-Clock Mode) Grayscale daa clock-in period Mode swich period Grayscale daa clock-in period DAI P[2] P[] P[] Don'care Don'care Q[255] Q[254] Q[] Don'care R[255] R[254] DAO * O[] ERR[]* 2 P[255] P [254 ] P[253] P[252] Q[255] *5 Q[254] Couner rese LAT *3 (exernal) (inernal) OUTn *4 (curren ) Frame Daa O Frame Daa P Frame DaaQ * REM, ARM, IGM is configered by defaul. They can swich o FEM, OSM, EGM accordingly. All regisers in wih be rese when any swich procees occur. *2 ERR[] is he error message of LED open deecion. *3 LAT is level rigger, no edge rigger. *4 Iou urn off when LAT is level,and urn on a he firs rising edge when LAT is level. *5 P[255],P[254], P[],O[],Q[255].Q[254], Q[],R[255],R[254], are serial daa for. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 2

22 Timing Diagram (Exernal-Clock Mode swich o Inernal-Clock Mode) Grayscale daa clock-in period Mode swich period Grayscale daa clock-in period DAI R[2] R[] R[] Don'care Don'care S[255] S[254] S[] Don'care T[255] T[254] DAO * Q[] ERR[]* 2 R[255] R[254] R[253] R[253 ] R[252 ] *5 S [255] S[254] Couner rese LAT *3 (exernal) (inernal) OUTn *4 (curren ) Fr ame Daa Q Frame Daa R Frame Daa S * REM, ARM, IGM is configered by defaul. They can swich o FEM, OSM, EGM accordingly. All regisers in wih be rese when any swich procees occur. *2 ERR[] is he error message of LED open deecion. *3 LAT is level rigger, no edge rigger. *4 Iou urn off when LAT is level,and urn on a he firs rising edge when LAT is level. *5 R[255],R[254], R[],S[255].S[254], S[],T[255],T[254], are serial daa for. on off 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 2

23 Oupu Modulaion Technique provides a new LED drive echnique of oupu modulaion. I mixes radiional Pulse Widh Modulaion (PWM) represened by LSB 2 bi wih Sequenial Spli Modulaion (SSM) represened by MSB 4 bi. The main benefis of SSM are o drive LED wih an equivalen er refresh rae (up o 38Hzn in when F = 25MHz) and change bi o nex bi smoohly. The relaionships beween PWM and SSM in ime domain can be refer o he diagram (no o scale) be: Bi[5:] MSB LSB XXXX,XXXXXXXX MSB LSB XXXX,XXXXXXXX Bi[:] (PWM) A complee modulaion cycle Bi[7:] (PWM) Bi[:8] (PWM) on off on off MSB LSB XXXX,XXXXXXXX MSB LSB XXXX,XXXXXXXX MSB LSB XXXX,XXXXXXXX MSB LSB XXXX,XXXXXXXX Bi[:8] (PWM) Bi[7:] (PWM) Bi[7:] (PWM) Bi[:] (PWM) Bi[7:] (PWM) Bi[:] (PWM) Bi [7:] (PWM) Bi[:] (PWM) on off on off on off on off MSB LSB XXXX,XXXXXXXX MSB LSB XXXX,XXXXXXXX Bi[7:] (PWM) Bi[7:] (PWM) clocks Bi[:] (PWM) Bi[:] (PWM) on off on off Ulra High Resoluion Curren Oupus could provide 6-bi linear PWM conrol curren oupus for each channel. There are wo advanages for sysem design. One is has sufficien bi resoluion (65536 seps), no only LED color informaion bu addiional daa such as global brighness, do correcion, and gamma correcion can be represened by he proper algorihms. The oher is o reduce a lo of clock and daa rae compared o convenional ON-OFF ype LED drivers. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 22

24 Global Brighness Conrol has no buil-in global brighness conrol feaure. In order o obain a er resoluion of global brighness conrol effec, wo mehods could be uilized. Here show differen ways o adjus he Rrex value or volage drop across he exernal resisor. Please see he reference circui be: Oupu o Oupu Delay has build-in oupu o oupu delay wih a special arrangemen. This arrangemen help chip avoid noise cause by large curren during channels swiching. The arrangemen deails are shown as foling able. Channel Delay unis channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 23

25 Power Dissipaion The power dissipaion of a semiconducor chip is limied o is package and ambien emperaure, in which he device requires he maximum oupu curren calculaed for given operaing condiions. The maximum alable power consumpion can be calculaed by he foling equaion: Pd(max)(Wa) = Tj(juncion emperaure)(max)( C) Ta(ambien emperaure)( C) Rh(juncion-o-air hermal resisance)( C/Wa) The relaionship beween power dissipaion and operaing emperaure can be refer o he figure be: PD - Ta curve Power Dissipaion Pd(W) Tj(max)=5 C TSSOP24E Rh(TSSOP24E=3 C/Wa Rh(SOP24B)=57 C/Wa SOP24B Rh(DIP24B)=67 C/Wa DIP24B Rh(SSOP24)=7 C/Wa SSOP Ambien Temperaure Ta ( ) The power consumpion of IC can be deermined by he foling equaion and should be less han he maximum alable power dissipaion: 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 24

26 Typical Applicaion 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 25

27 Package Ouline Dimension -DIPB D 24 3 E E E2 2 L A A2 A SEATING PLANE b e b DIMENSIONS IN INCH DIMENSIONS IN MM SYMBOLS MIN. MAX. MIN. MAX. A A A b.4.6 b D E.3BSC 7.62BSC E E e L Θ channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 26

28 Package Ouline Dimension -SSOP D 24 3 E E 2 A C GAUGE PLANE A2 A b e.4 SEATING PLANE L L A DETAIL A DIMENSIONS IN INCH DIMENSIONS IN MM SYMBOLS MIN. MAX. MIN. MAX. A A A b C D E E e.25 BSC..635 BSC L L.4 BSC.4 BSC Θ channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 27

29 Package Ouline Dimension -SOPB DIMENSIONS IN INCH DIMENSIONS IN MM SYMBOLS MIN. MAX. MIN. MAX. A A A b c D E e.394 BSC. BSC E L θ 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 28

30 Package Ouline Dimension -TSSOPE (exposed pad) 24 3 D E E E2 2 e b S D.25mm A2 A L GAUGE PLANE SEATING PLANE.5 A L DIMENSIONS IN INCH DIMENSIONS IN MM SYMBOLS MIN. MAX. MIN. MAX. A A A b D E E.252 BSC 6.4 BSC e.26 BSC.65 BSC L.39 REF. REF. L S Θ 8 8 E D channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 29

31 The producs lised herein are designed for ordinary elecronic applicaions, such as elecrical appliances, audio-visual equipmen, communicaions devices and so on. Hence, i is advisable ha he devices should no be used in medical insrumens, surgical implans, aerospace machinery, nuclear power conrol sysems, disaser/crime-prevenion equipmen and he like. Misusing hose producs may direcly or indirecly endanger human life, or cause injury and propery loss. Silicon Touch Technology, Inc. will no ake any responsibiliies regarding he misusage of he producs menioned above. Anyone who purchases any producs described herein wih he above-menioned inenion or wih such misused applicaions should accep full responsibiliy and indemnify. Silicon Touch Technology, Inc. and is disribuors and all heir officers and employees shall defend joinly and severally agains any and all claims and liigaion and all damages, cos and expenses associaed wih such inenion and manipulaion. 6-channel 6-bi PWM Consan Curren LED Driver Version:PRE. Preliminary Page 3