Efficiency (%) I LED. Fig. 1 Li-Ion Powered Driver for three white LEDs

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1 . 4MHz Thin Package Current-Mode Step-Up DC/DC Converter FETURES Fixed Frequency.4MHz Current-Mode PWM Operation. djustable Output Voltage up to 30V. Guaranteed 3V/ 200m Output with 5V Input. 2.5V to 0V Input Range. Maximum 0.µ Shutdown Current. Programmable Soft-Start. Tiny Inductor and Capacitors are allowed. Space-Saving SOT-23-6 and TSOT-23-6 Package. PPICTIONS White ED Backlight. OED Driver. CD Bias DESCRIPTION IC896 is a current-mode pulse-width modulation (PWM), step-up DC/DC Converter. The built-in high voltage N-channel MOSFET allows IC896 for step-up applications with up to 30V output voltage, as well as for Single Ended Primary Inductance Converter (SEPIC) and other low-side switching DC/DC converter. The high switching frequency (.4MHz) allows the use of small external components. The Soft-Start function is programmable with an external capacitor, which sets the input current ramp rate. The IC896 is available in a space-saving SOT-23-6 and TSOT-23-6 package. TYPIC PPICTION CIRCUIT V 3.3V or 4.2V C 4.7µF OFF ON IC D CH52S-30 ZD BZV55-B2.8V~2.2V KΩ 62 I ED µf Efficiency (%) Fig. i-ion Powered Driver for three white EDs V =4.2V 72 : GTSK-5-50M (5µH) 70 : GTSK-5-00M (0µH) ED Current (m) V =3.3V nalog Integrations Corporation Si-Soft Research Center DS-896G , No., i-hsin Rd. I, Science Park, Hsinchu 300, Taiwan, R.O.C. TE: FX:

2 V D 3.6V or CH52S V C ZD 4.7µF BZV55-B V~24.5V IC OFF ON 5 2 KΩ 62 I ED µf Efficiency (%) V =4.2V V =3.6V : GTSK-5-50M (5µH) : GTSK-5-00M (0µH) ED Current (m) ORDERG FORMTION Fig. 2 i-ion Powered Driver for six white EDs IC896XXXX Example: IC896PKTR PCKG TYPE TR: TPE & REE BG: BG PCKGE TYPE G: SOT-23-6 K: TSOT-23-6 P: ED FREE COMMERCI G: GREEN PCKGE in ead Free TSOT-23-6 Package & Tape & Reel Packing Type IC896PGTR in ead Free SOT-23-6 Package & Tape & Reel Packing Type P CONFIGURTION SOT-23-6 / TSOT-23-6 FRONT VIEW : 2: : 896/896P 4: 5: 6: 2 3 Note: Pin is determined by orienting the package marking as shown. TSOT-23-6 Marking Part No. IC896PK IC896GK Marking 896PK 896GK SOT-23-6 Marking Part No. IC896PG IC896GG Marking 896P 896G 2

3 BSOUTE MXIMUM RTGS to -0.3V to 33V to -0.3V to 6V, -0.3V to V to -0.3V to 6V Pin RMS Current 0.6 Continuous Power Dissipation 727mW Operating Temperature Range -40 C to 85 C Junction Temperature 25 C Storage Temperature Range -65 C to 50 C ead Temperature (soldering, 0s) 260 C bsolute Maximum Ratings are those values beyond which the life of a device may be impaired. TEST CIRCUIT D V 2.5V to 0V C 0µF/6V GTSK-5-00M(0uH) 6 4 U IC C4 0µF C5 µf V OUT

4 EECTRIC CHRCTERISTICS (V =V =3V, =, =Open, T =25 C, unless otherwise specified) (Note ) PRMETER SYMBO CONDITIONS M TYP MX UNITS Input Supply Range V V Output Voltage djust Range V OUT 30 V V Undervoltage ockout UVO V rising, 50mV hysteresis 2.2 V Quiescent Current Shutdown Supply Current ERROR MPIFIER I V =.3V, not switching V =.0V, switching 5 m V = 0, T = 25 C µ V = µ Feedback Regulation Set Point V V Input Bias Current I V =.24V 2 80 n ine Regulation 2.6V < V < 5.5V %/V OSCITOR Frequency f OSC KHz Maximum Duty Cycle DC % POWER SWITCH Steady State Output Current Io Refer to Fig. 3 On-Resistance R DS(ON) Vin = 5V.4 Ω V = 30V, T = 25 C 0. eakage Current I (OFF) V = 30V 0 SOFT-STRT Reset Switch Resistance Guaranteed By Design 00 Ω Charge Current V =.2V µ CONTRO PUT Input ow Voltage V I V, V = 2.5V to 0V 0.3 V Input High Voltage V IH V, V = 2.5V to 0V.0 V V =.8V Input Current I V = µ µ Note : Specifications are production tested at T =25 C. Specifications over the -40 C to 85 C operating temperature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC). 4

5 TYPIC PERFORMNCE CHRCTERISTICS Switching Frequency (MHz) V =3.6V Frequency (MHz) T =25 C Temperature ( C) Fig. 3 Switching Frequency vs. Temperature Supply Voltage (V) Fig. 4 Frequency vs. Supply Voltage R DS(ON) (Ω) Output Voltage (V) V =3.6V Supply Voltage (V) Fig. 5 R DSON vs. Supply Voltage Output Current (m) Fig. 6 oad Regulation (=0μH) Output Voltage (V) V =3.6V Supply Current (m) =.0V =.0V Output Current (m) Fig. 7 oad Regulation (=22μH) Supply Voltage (V) Fig. 8 Switching Current 5

6 TYPIC PERFORMNCE CHRCTERISTICS (Continued) (μ Supply Current ) =.3V =.0V Feedback Voltage (V) V =3.6V Supply Voltage (V) Fig. 9 Non-Switching Current Temperature ( C) Fig. 0 Feedback Pin Voltage Efficiency (%) V =2.7V V =2.5V V =4.2V V =3.6V V =3.3V Efficiency (%) V =3.3V V =3.6V V =4.2V V =5.0V V OUT =5.0V : GTSK-5-00M Output Current (m) Fig. Efficiency vs. Output Current (=0µH, test circuit refer to p.3) V OUT =2V : SF MR Output Current (m) Fig. 2 Efficiency vs. output current (=22µH, test circuit refer to p.3) Maximum Output Current (m) V OUT=5V V OUT =9V V OUT =3V V OUT =5V Maximum output current defined at 90% of no load output voltage Maximum Output Current (m) V OUT =20V V OUT =25V V OUT =30V Maximum output current defined at 90% of no load output voltage Supply Voltage (V) Fig. 3(a) Maximum Output current vs. Supply Voltage (: 0µH, test circuit refer to p.3) Supply Voltage (V) Fig. 3(b) Maximum Output Current vs. Supply Voltage (:22µH, test circuit refer to p.3) 6

7 TYPIC PERFORMNCE CHRCTERISTICS (Continued) V V SW V OUT V OUT I I Fig. 4 Operation Wave Form (V =5V; V OUT =2V, =22µH; =05K; =2K;=nF;I OUT =200m, test circuit refer to p.3) Fig. 5 Operation Wave Form (V =3V;V OUT =5V;=0µH;=36K;=2K; =39pF;I OUT =200m, test circuit refer to p.3) V OUT V OUT I I Fig. 6 oad Step Response (V =3.3V; V OUT =5V;=0µH;I OUT =5m to 200m, test circuit refer to p.3) Fig. 7 oad Step Response (V =5V ; V OUT =2V ;=22µH;I OUT =5m to 50m, test circuit refer to p.3) V OUT I Fig. 8 Start-Up from Shutdown (V =3.3V ;V OUT=3V ;R OD=300Ω, test circuit refer to p.3) 7

8 BOCK DIGRM V Q R4 R3 Q2 8 - Error mp RC PWM Comparator - Control PWM/PFM Control ogic Driver Soft Start 4µ I9 CC Slope Compensation Current MP x 5.4MHz Oscillator - x RS x20 P DESCRIPTIONS P : P 2: - Ground. - Power Switching Connection. Connect to inductor and output rectifier. Keep the distance between the components as close to as possible. P 3: - Feedback Input. Connect a resistive voltage-divider from the output to to set the output voltage. P 4: - Shutdown Input. Drive low to turn off the converter. To automatically start the converter, connect to. Drive with a slew rate of 0.V/µs or greater. Do not leave unconnected. draws up to 50µ. P 5: - Soft-Start Input. Connect a soft-start capacitor from to in order to soft-start the converter. eave open to disable the soft-start function. P 6: - Internal Bias Voltage Input. Connect to the input voltage source. Bypass to with a capacitor sitting as close to as possible. 8

9 PPICTION FORMTION Inductor Selection 5µH inductor is recommended for most IC896 applications. lthough small size and high efficiency are major concerns, the inductor should have low core losses at.4mhz and low DCR (copper wire resistance). Capacitor Selection The small size of ceramic capacitors makes them ideal for IC896 applications. X5R and X7R types are recommended because they retain their capacitance over wider ranges of voltage and temperature than other types, such as Y5V or Z5U. 4.7µF input capacitor and a µf output capacitor are sufficient for most IC896 applications. Diode Selection Schottky diodes, with their low forward voltage drop and fast reverse recovery, are the ideal choices for IC896 applications. The forward voltage drop of a Schottky diode represents the conduction losses in the diode, while the diode capacitance (CT or CD) represents the switching losses. For diode selection, both forward voltage drop and diode capacitance need to be considered. Schottky diodes with higher current ratings usually have lower forward voltage drop and larger diode capacitance, which can cause significant switching losses at the.4mhz switching frequency of IC896. Schottky diode rated at 00m to 200m is sufficient for most IC896 applications. ED Current Control ED current is controlled by feedback resistor ( in Fig. ). The feedback reference is.23v. The ED current is.23v/. In order to have accurate ED current, precision resistors are preferred (% recommended). The formula for selection is shown below. =.23V/I ED () Open-Circuit Protection In the cases of output open circuit, when the EDs are disconnected from the circuit or the EDs fail, the feedback voltage will be zero. IC896 will then switch to a high duty cycle resulting in a high output voltage, which may cause SW pin voltage to exceed its maximum 30V rating. zener diode can be used at the output to limit the voltage on SW pin (Fig. 20). The zener voltage should be larger than the maximum forward voltage of the ED string. The current rating of the zener should be larger than 0.m. Dimming Control There are three different types of dimming control circuits as follows:. Using a PWM signal PWM brightness control provides the widest dimming range by pulsing EDs on and off at full and zero current, repectively. The change of average ED current depends on the duty cycle of the PWM signal. Typically, a 0.kHz to 0kHz PWM signal is used. Two applications of PWM dimming with IC 896 are shown in Fig 2. One, as fig. 2(a), uses PWM signal to drive pin directly for dimming control. The other, as fig. 2(b), employs PWM signal going through a resistor to drive pin. If the pin is used, the increase of duty cycle results in ED brightness enhancement. If the pin is used, on the contrary, the increase of duty cycle will decrease its brightness. In this application, EDs 9

10 are dimmed by pin and turned off completely by. 2. Using a DC Voltage For some applications, the preferred method of a dimming control uses a variable DC voltage to adjust ED current. dimming control using a DC voltage is shown as Fig. 22. s DC voltage increases, the voltage drop over increases and the voltage drop over decreases. Cautiously selecting and R3 is essential so that the current from the variable DC source is much smaller than the ED current and much larger than the pin bias current. With a VDC ranging from 0V to 5V, the selection of resistors in Fig. 22 results in dimming control of ED current from 20m to 0m, respectively. 3. Using a Filtered PWM Signal Filtered PWM signal can be considered as an adjustable DC voltage. It can be used to replace the variable DC voltage source in dimming control. The circuit is shown in Fig. 23. V 3.3V to 4.2V C 4.7µF 0µH SF MR0 D 0540 ZD BZV55-B24 µf U IC V~24.5V 6 OFF ON KΩ 62Ω I OUT =I ED =20m Fig. 9 White ED Driver with Open-Circuit Protection IC896 ZD IC896 ZD PWM KΩ 62Ω OFF ON K R3 30K 62 PWM (a) (b) Fig. 20 Dimming Control Using a PWM Signal 0

11 IC896 ZD OFF ON IC896 ZD KΩ R3 3.3KΩ 82Ω 20m~0m OFF ON KΩ R3 3.3KΩ 82Ω R4 4KΩ VDC 0V~5V C 0.µF PWM Fig. 2 Dimming Control Using a DC Voltage Fig. 22 Dimming Control Using a Filtered PWM Signal PPICTION EXMPES V 3V to 4.2V C 4.7µF 0µH SF MR0 D 0504 ZD µf U IC896 BZV55-B V~24.5V 6 OFF ON KΩ 62Ω R3 62Ω I OUT =I ED =20m Fig. 23 -Cell i-ion Powered Driver for eight White EDs with Open-Circuit Protection

12 * Vin C 33uF 0.033uF IC896 / 2k D 4 * 00p C4 0u/25V Vout C5 0.uF Vout * * 5V 9V 2V 8V 24V 36K 75k 05k 60k 220k 0uH 0uH 0uH 22uH 22uH Fig. 24 Typical Step up pplication Circuit V 3V to 4.2V C4 4.7µF/6.3V OFF ON C5 22uH SF MR73 IC C µf 2k D 35k 0540 C6 00pF D2 BT54S V OUT2-5V/5m µf/6v V OUT 5V/5m µf/6v Fig. 25 -Cell i-ion to ±5V/5m Dual Output Converter for CD Bias 0.0u D2 BT54S V OUT =40V/0m C4 0.uF 5V C 4.7uF U 22uH SW D 054 C5 0.0u 3M IC896 0nF 9k Fig. 26 High 40V Output Voltage for Electrophoretic Display (EPD) pplication 2

13 C6 D3 Q2 MMBT2907 Vout3=-7V uf BT54WS C7 uf R3 2.2K D5 7.7V C uf D2 C8 uf C9 uf Vout2=20V Vin C 4.7uF SW IC896 22uH BT54WS D uF / 2K 85K 00pF C4 0uF/25V C5 0.uF Vout=0V Fig. 27 Three output voltage for CD 3

14 PHYSIC DIMENSIONS (unit: mm) TSOT-23-6 D S Y M B O M. TSOT-23-6 MIIMETERS MX. E E e e SEE VIEW B b c D b E WITH PTG c E e BSC.70 BSE MET SECTION - e BSC 0.60 REF θ 0 8 VIEW B θ GUGE PNE SETG PNE Note :. Refer to JEDEC MO Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 6 mil per side. 3. Dimension "E" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. 4

15 SOT-23-6 D E E S Y M B O M. SOT-23-6 MIIMETERS MX e e SEE VIEW B b c b D E WITH PTG c E e BSC.70 BSE MET SECTION - e BSC 0.42 REF θ 0 8 VIEW B θ GUGE PNE SETG PNE Note :. Refer to JEDEC MO-78B. 2. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 0 mil per side. 3. Dimension "E" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. Note: Information provided by IC is believed to be accurate and reliable. However, we cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an IC product; nor for any infringement of patents or other rights of third parties that may result from its use. We reserve the right to change the circuitry and specifications without notice. ife Support Policy: IC does not authorize any IC product for use in life support devices and/or systems. ife support devices or systems are devices or systems which, (I) are intended for surgical implant into the body or (ii) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 5