ST763

ST763A STMICROELECTRONICS | Alldatasheet

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Technical content

■ OUTPUT VOLTAGE 3.3V ■ SUPPLY VOLTAGE RANGE FROM 3.3V TO 11V ■ GUARANTEED OUTPUT CURRENT: 500mA ■ TYPICAL OPERATION FREQUENCY: 200KHz ■ VERY LOW QUIESCENT CURRENT: 0.6mA ON MODE 0.2 µA OFF MODE ■ SWITCH ON/OFF CONTROL ■ TYPICAL EFFICENCY: 90% ■ OPERATING TEMPERATURE RANGE: -40°C TO 85°C ■ AVAILABLE IN SO-8 AND DIP-8 PACKAGES

DESCRIPTION

The ST763A is a step-down switching regulator . It operates from 3.3V to 11V giving a fixed 3.3V output voltage, delivering up to 500mA. The mainly features are typical efficiency of 90%, quiescent current of 0.6mA, and only 0.2µA in shut-down. The PWM current mode control provides precise output regulation and very good transient response. Output voltage accuracy is guaranteed to be ±5% over line, load and temperature variations. A minimum number of external components is used and the fixed frequency switching allows easy filtering of output ripple and noise. Other features of this ddevice are cycle-by-clicle current limiting, overcurrent limiting, under voltage lockout and programmable soft-start protection. A 22µH inductor works in most applications, so no sophisticated design is necessary. Package available are SO-8 and DIP-8. Typical application are in 5V to 3.3V converters, cellular phones, portable instruments, hand-held computers, and peripherals. ST763A SERIES 3.3V STEP DOWN CURRENT MODE PWM DC-DC CONVERTERS SCHEMATIC DIAGRAM DIP-8 SO-8

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. THERMAL DATA (*) This value depends from thermal design of PCB on which the device is mounted. ORDERING CODES Symbol Parameter² Value Unit VCC DC Input Voltage -0.3 to 12 V VLX Switch Pin Voltage -0.3 to (V CC + 0.3) V VSHDN Shutdown Voltage (SHDN) -0.3 to (V CC + 0.3) V VS,VC Soft Start (SS) and Compensation Capacitor (CC) Pins Voltage -0.3 to (VCC + 0.3) V ILX Switching Peak Current 2A IREF Reference Current 2.5 mA PTOT Continuous Power Dissipation at TA=70°C (DIP-8) (SO-8) 550 344 mW mW Tstg Storage Temperature Range -40 to +150 °C Top Operating Junction Temperature Range (AC series) (AB series) 0 to +70 -40 to +85 Symbol Parameter SO-8 DIP-8 Unit R thj-amb Thermal Resistance Junction-ambient (*) 160 100 °C/W TYPE DIP8 SO-8 SO-8 (T&R) ST763AB ST763ABN ST763ABD ST763ABDTR ST763AC ST763ACN ST763ACD ST763ACDTR

CONNECTION DIAGRAM (top view) PIN DESCRIPTION Pin N° Symbol Name and Function 1 SHDN Shutdown control (active low): If connected to GND the IC is in shutdown. Connect to VCC for normal operation (ON MODE) 2 REF Reference Output Voltage:(1.25V): Bypass to GND with 47nF capacitor

3 SS Soft Start: a capacitor between SS and GND provides soft-start and short-circuit

protections.

4 CC Compensation Capacitor Input: externally compensates the outer (voltage)

feedback loop. Connect to OUT with 330pF capacitor 5 OUT Output Voltage Sense Input: provides regulation of feedback sensing. Connect to 3.3V output.

6 GND Ground

7 LX Switch Output. Drain of internal P-Channel Power MOSFET 8V CC Supply Voltage Input. Bypass to GND with 1µF ceramic capacitance and large value electrolytic capacitor in parallel. The 1µF capacitor must be as close as possible to the GND and VCC pins

ELECTRICAL CHARACTERISTICS (VCC =5V, IO = 0mA, TA = TMIN to TMAX , unless otherwise specified.) TYPICAL APPLICATION CIRCUIT Symbol Parameter Test Conditions Min. Typ. Max. Unit VCC Input Voltage 3.3 11 V VO Output Voltage V CC = 4 to 11V I O =0 to 300mA VCC = 4.75 to 11V IO =0 to 500mA 3.135 3.135 3.3 3.3 3.465 3.465 V V ΔVO Line Regulation 0.13 %/V ΔVO Load Regulatio I O = 1 to 500mA 0.005 %/mA η Power Efficency I O =300mA IO =100mA ISUPPLY Supply Current ON Mode (Including Switch Current) OFF Mode 0.6 0.2 2.5 100 mA µA VIH SHDN Input High Threshold 2 V VIL SHDN Input Low Threshold 0.25 V ISHDN Shutdown Input Leakage Current 1 µA VLOCK Under Voltage Lockout V CC Falling 2.7 3 V R DS(on) LX On Resistance I LX=500mA 1 Ω ILEAK LX Leakage Current V CC = 12V V LX = 0V 10 nA VREF Reference Voltage T A = 25°C 1.18 1.25 1.32 V ΔVREF Temeperature Reference Drift TA = TMIN to TMAX 50 ppm/°C fOSC Switching Frequency 159 200 212.5 KHz R C Compensation Pin Impedance 7500 Ω CC SS REF SHDN Vcc Lx OUT GND 470 pF 220 µF 1 µF 1500 pF 100 µF22 µH Vout Vin 0.047 µF STPS330U

DIM. mm inch A3 . 3 0 . 1 3 0 a1 0.7 0.028 B 1.39 1.65 0.055 0.065 B1 0.91 1.04 0.036 0.041 b0 . 5 0 . 0 2 0 b1 0.38 0.5 0.015 0.020 D9 . 8 0 . 3 8 6 E8 . 8 0 . 3 4 6 e2 . 5 4 0 . 1 0 0 e3 7.62 0.300 e4 7.62 0.300 F7 . 1 0 . 2 8 0 I4 . 8 0 . 1 8 9 L3 . 3 0 . 1 3 0 Z 0.44 1.6 0.017 0.063 P001F Plastic DIP-8 MECHANICAL DATA

DIM. mm inch A1 . 7 5 0 . 0 6 8 a1 0.1 0.25 0.003 0.009 a2 1.65 0.064 a3 0.65 0.85 0.025 0.033 b 0.35 0.48 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.25 0.5 0.010 0.019 c1 45 (typ.) D 4.8 5.0 0.188 0.196 E 5.8 6.2 0.228 0.244 e1 . 2 7 0 . 0 5 0 e3 3.81 0.150 F 3.8 4.0 0.14 0.157 L 0.4 1.27 0.015 0.050 M0 . 6 0 . 0 2 3 S8 ( m a x . ) 0016023 SO-8 MECHANICAL DATA

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