Liteon Semiconductor Corporation LSP3601 Step-Up DC/DC Controller

Transcription

1 Liteon Semiconductor Corporation FEATURES Wide supply voltage operating range: 1.8 to 15V Reference voltage precision: 4% Low current consumption: Operation Mode 5.5mA Standby Mode: 1µA High speed oscillator frequency: 1MHz max Programmable Soft Start function (SS) Short Circuit Protection function (SCP) Totem-pole output with adjustable on/off current (for NPN transistors or n-channel MOSFET) Logic level control stand-by mode function Package: SOP8/MSOP8/TSSOP8 GENERAL DESCRIPTION The is a boost topology switching regulator control IC for battery-used applications field. The includes a totem-pole single output stage for driving NPN transistor or N-MOS, high precision reference (0.5V) for comparing output voltage with feedback amplifier, an internal dead-time control for controlling the minimum duty cycle, programmable soft start with short circuit protection function and logic level control for operating mode or standby mode. TYPICAL APPLICATION Digital Camera PDA Portable Equipment PIN ASSIGNMENT SOP8 MSOP8 TSSOP8 PIN DESCRIPTION Name No. I/O Description FB 1 I Error amplifier inverting input pin SCP 2 I Connected a capacitor Soft start and SCP function pin V CC 3 P IC Power supply BR/CTL 4 I Output current setting and control pin OUT 5 O Totem-pole output GND 6 P IC ground OSC 7 I Capacitor and resistor connected for the frequency of oscillation COMP 8 O Error amplifier compensation output 1/14 Rev1.3

2 FUNCTIONAL BLOCK DIAGRAM Liteon Semiconductor Corporation Reference voltage supply 1.25V - + Error Amp. 0.5V V- 0.1V- 36kΩ 500Ω Sawtooth wave oscillator 0.1V PWM Comp. DTC0.6V Output drive control circuit 0.22V 30KΩ 5 8 Soft start SCP ABSOLUTE MAXIMUM RATINGS Power supply voltage +15V Output source current -50mA Output sink current +50mA SOP8 T a mW Allowable dissipation MSOP8 T a mW TSSOP8 T a mW Operating temperature Storage temperature SOP8 lead Temperature (solding,10 sec) +260 TSSOP8 Lead Temperature (solding,10 sec) +260 MSOP8Lead Temperature (soldering,10 sec) +260 DC Electrical Characteristics Under Voltage Lock-Out section (U.V.L.O.) Low threshold voltage V LOW 0.9 V Upper threshold voltage V UPPER V Soft Start section (S.S.) Input source current I SS V SCP =0V A Soft start threshold voltage V SST V 2/14 Rev1.3

3 Liteon Semiconductor Corporation DC ELECTRICAL CHARACTERISTICS (CONTINUED) Short Circuit Protection section (S.C.P.) Input source current I SCP V SCP =0V A S.C.P. threshold voltage V SCP V Oscillator section Oscillation frequency f R T =3.0KΩ, C T =270pF KHz Frequency change with voltage f/ V V CC =2V to 15V 2 10 % Frequency change with temperature f/ T T a =0 to 85 5 % Idle Period Adjustment section Maximum duty cycle T DUTY R T =3.0KΩ, C T =270pF,V FB =0.8V % Total device section Stand-by current I STANDBY Pin4 is open or V CC 1 µa Average supply current I AVE R B =390Ω, V CC =0 20V ma Error Amplifier section Input threshold voltage V FB V COMP =450mV mv V T change with voltage V FB / V V CC =2V to 15V 5 20 mv V T change with temperature V FB / V T a =-10 to 85 1 % Input basic current I B µa Voltage Gain A V 100 V/V Frequency bandwidth BW A V =0dB 6 MHz Output voltage Positive V POS Swing Negative V NEG V Output source current I SOURCE µa V Output sink current I COMP =450mV SINK µa Output section Output high voltage V OH1 R B =390Ω,I O =-15mA V Output high voltage V OH2 R B =750Ω,I O =-10mA,V CC =1.8V V Output saturation voltage V Ol1 R B =390Ω,I O =15mA V Output saturation voltage V Ol2 R B =750Ω,I O =10mA,V CC =1.8V V Output source current I OSOURCE R B =390Ω,V O =-0.9V ma Output sink current I OSINK R B =390Ω,V O =-0.3V ma Internal pull-down resistor R O KΩ Output Current Setting / Control section Pin voltage V BR R B =390Ω V Input off condition I OFF µa Input on condition I ON -4.5 µa Pin current range I BR ma 3/14 Rev1.3

4 TYPICAL CHARACTERISTICS Liteon Semiconductor Corporation -10 Supply c urr ent (ma) Supply voltage vs. Supply current Ta=25 RB=390Ω Supply voltage Vcc (V) Figure 1 Supply voltage vs. Input threshold voltage 1.2 Input threshold voltage Vt (V) Ta= Supply voltage Vcc (V) Figure 2 Input threshold voltage variation ratio V/Vt (%) Ambient temperature vs.input threshold voltage variation ratio Vcc=2V Ambient Temperature Ta ( ) Figure 3 High level output voltage Vout(V) High level output Vcc=2V RB=390Ω Ta= High level output current Iout (ma) Figure 4 4/14 Rev1.3

5 TYPICAL CHARACTERISTICS (CONTINUED) Liteon Semiconductor Corporation Low level output voltage Vout(V) Low level output Vcc=2V RB=390Ω Ta=25 Output source current Iout(mA) BR/CTL pin current vs. Output source current Vcc=2V Vout=0.9V Ta= Low level output current Iout (ma) Figure BR/CTL pin current IBR (ma) Figure 6 BR/CTL pin voltage VBR(mV) BR/CTL pin current vs. BR/CTL pin voltage Vcc=2V Ta=25 Supply current Icc(mA) BR/CTL pin current vs. Supply current Vcc=2V Ta= BR/CTL pin current IBR(mA) Figure BR/CTL pin current IBR( A) Figure 8 5/14 Rev1.3

6 TYPICAL CHARACTERISTICS (CONTINUED) Liteon Semiconductor Corporation Frequency variation ratio f/f(%) Supply voltage vs. Frequency variation ratio Ta=+25 RT=3.0KΩ CT=270PF Supply voltage Vcc (V) Figure 10 Frequency variation ratio f/f(%) Ambient temperature vs. Frequenc variation ratio 30 Vcc=2V 10 RT=3.0KΩ CT=270PF Ambient Temperature Ta ( ) Figure 11 6/14 Rev1.3

7 Liteon Semiconductor Corporation TIMING WAVEFORM COMP pin voltage Reference input for short circuit detection comparator Idle period setting voltage Soft start setting voltage OUT pin waveforms SCP pin waveforms ON Power supply control SW OFF Soft start ts Output short circuit tpe Output short circuit Short circuit detection DETAILED DESCRIPTION Voltage reference A 1.25V regulator operating from V CC is used to power the internal circuitry of the. An internal resister divider provides 0.5V reference for the error amplifier, Soft-start (typ. 0.9V) and SCP (typ.0.8v). Error amplifier The error amplifier compares a sample of the dc-dc converter output voltage to the 0.5V reference and generates an error signal for the PWM comparator. Output voltage of the dc-dc converter is setting with the resistor divider using the following expression (see fig12): V OUT = (1+R 1 / R 2 ) 0.5 Vout R1 1 Error Amplifier 36K - R V C1 7/14 Rev1.3

8 Liteon Semiconductor Corporation Figure 12. Error Amplifier with Feedback resistance divider Oscillator The oscillator frequency can be set between 20 KHz and 500 KHz by connecting a resistor and a capacitor at OSC pin of to ground. The oscillator frequency can be determined by using the graph shown in figure 9. The oscillator output is a sawtooth wave with a minimum value of approximately 0.1V and a maximum value of approximately 0.6V. The PWM comparator compares the oscillator voltage with error amplifier output voltage; internal DTC voltage (typ.0.6v) and soft start setting voltage. When the sawtooth wave is lower than the above three output voltage, the output of is high (Turn on NPN transistor or NMOS). Under voltage lockout (UVLO) The under voltage lockout circuits turn the output off whenever the supply voltage drop too low (approximately 0.9V at 25 ) for proper operation.a hysterics voltage of 200 mv eliminates false triggering on noise and chattering. Soft Start / Short-circuit protection (S.S. / S.C.P.) The soft start is function after power on, and the interval of the soft start time is determined by capacitor connected to SCP pin (pin 2). When soft start function finished, the internal soft start voltage is setting high, but external SCP pin is setting low in order to change to short circuit detection / protection function. The time of soft start is following expression: T SS =0.35 C[ F] The short circuit protection is functional due to a heavy loading drop and output of error amplifier (COMP pin) is maintain a V POS (typ.0.87v), the capacitor is charged until SCP threshold voltage (typ.0.8v), then output is disable (internal pull-low ) and the capacitor is discharged to low. The time of short circuit protection is following expression: T SCP =0.8 C[ F] Output transistor The has a totem-pole transistor with a 40 ma source/sink current rating to drive an external NPN transistor or NMOS transistor directly. The driving current capability depends on a resistor R that is connected to BR/CTL pin (pin4) of. (see fig.13) 4 BR/CTL R Control Q1 Figure13. Output transistor driving control circuit BR/CTL pin can also use to control the output of for disable or enable function of system. Control Pin Q1 BR/CTL Pin Output Transistor Function Mode Low Off Open Disable Stand-by High On Bias Current Enable Operation 8/14 Rev1.3

9 Liteon Semiconductor Corporation APPLICATION NOTE (1) Figure 14.DC 12V to DC 24V Boost Regulator Figure15. DC2.5V DC6V to DC3.3V SEPIC Regulator 9/14 Rev1.3

10 APPLICATION NOTE (2) Liteon Semiconductor Corporation Figure16. Charge Pump DC-DC Converter Circuits 10/14 Rev1.3

11 ORDERING INFORMATION Liteon Semiconductor Corporation MARKING INFORMATION 1) SOP-8L LOGO LSC YYWWXX Part ID YYWW XX Internal Code Date code YY Year(09=2009,10=2010,11=2011,12= ) WW Week(01~53) 2) MSOP-8L LOGO LSC VYWZ Part ID V YW Z Internal Code Date Code Y Year(09=2009,10=2010,11=2011,12= ) W Week Week Code# A B C D Week Code# E F G H J K L M N P Q R S Week Code# T U V W X Y Z a b c d e f Week /53 Code# g h I m n p q s t u v w x Output Voltage Blank=ADJ 3) TSSOP-8L LSC YYWWXX LOGO Part ID YYWW XX Internal Code Date code YY Year(09=2009,10=2010,11=2011,12= ) WW Week(01~53) 11/14 Rev1.3

12 PACKAGE INFORMATION 1) SOP8 Liteon Semiconductor Corporation E H L VIEW A 7 ο (4 ) D 7 ο (4 ) A2 A ο e B A1 C VIEW A Y Symbol Dimensions In Millimeters Dimensions In Inches Min. Nom. Max. Min. Nom. Max. A A A B C D E e H L Y θ 0 ο 8 ο 0 ο 8 ο 12/14 Rev1.3

13 Liteon Semiconductor Corporation 2) MSOP8 D E1 E GAGE PLANE L 0.25 DETAIL A PIN INDICATOR Ф0.45mm 0.038DP SURFACE POLISHED 12 ο (4 ) DETAIL A A2 A A1 e b C y Symbol Dimensions In Millimeters Dimensions In Inches Min. Nom. Max. Min. Nom. Max. A A A b C D E E e L y θ 0 ο 3 ο 6 ο 0 ο 3 ο 6 ο 13/14 Rev1.3

14 Liteon Semiconductor Corporation 3) TSSOP8 PIN 1 INDICATOR Φ0.70mm SURFACE POLISHED E1 E L1 L θ DETAILA D e E1 L1 A2 A DETAILA A1 b y C Symbol Dimensions In Millimeters Dimensions In Inches Min. Nom. Max. Min. Nom. Max. A A A b C D E E e L L y ο 4 ο 8 ο 0 ο 4 ο 8 ο 14/14 Rev1.3