L6902D

Output Power :
Mounting Style : SMD/SMT
Packaging : Tube
Output Current : 1 A
Package / Case : SO-8
Operating Temperature Range : - 40 C to + 150 C
Output Voltage : 34 V
Input Voltage : 8 V to 36 V
Switching Frequency : 212 KHz to 287 KHz


Features:

· UP TO 1A OUTPUT CURRENT
· OPERATING INPUT VOLTAGE FROM 8V TO 36V
· PRECISE 3.3V (±2%) REFERENCE VOLTAGE
· 5% OUTPUT CURRENT ACCURACY
· OUTPUT VOLTAGE ADJUSTABLE FROM 1.235V TO 34V
· 250KHz INTERNALLY FIXED FREQUENCY
· VOLTAGE FEEDFORWARD
· ZERO LOAD CURRENT OPERATION
· ADJUSTABLE CURRENT LIMIT
· PROTECTION AGAINST FEEDBACK DISCONNECTION
· THERMAL SHUTDOWN


Application

· CHARGERS FOR NiCd, NiMH BATTERIES AND PREREGULATOR FOR LITHIUM-ION BATTERIES
· ADJUSTABLE CURRENT GENERATOR
· SIMPLE STEP-DOWN CONVERTERS WITH ADJUSTABLE CURRENT LIMIT
· BATTERY EQUIPPED SYSTEMS
· DISTRIBUTED POWER SUPPLY
· MOBILE PC & SUBNOTEBOOK


Pinout




Specifications

Symbol	Parameter	Value	Unit
V8	Input Voltage	40	V
V1	Output DC voltageOutput peak voltage at t = 0.1s	-1 to 40 -5 to 40	V V
I1	Maximum output current	Internally limited
V4, V5	Analog pins	4	V
V2, V3	Analog pins	-0.3V to VCC	V
Ptot	Power dissipation at Tamb 70 °C	0.7	V
Tj	Operating junction temperature range	-40 to 150	°C
Tstg	Storage temperature range	-55 to 150	°C

Description

The L6902D is a complete and simple step down switching regulator with adjustable current limit. Based on a voltage mode structure it integrates a cur rent error amplifier to have a constant voltage and constant rent control.

By means of an on board current sense resistor and the availability of the current sense pins (both compatible to Vcc and for Cs- compatible with GND too) a current limit programming is very simple and accurate (±5%). Moreover constant current control can be used to charge NiMH and NiCd batteries.

The L6902D can be used as a standard DC/DC converter with adjustable current limit (set by using the external sense resistor).

The internal robust P-Channel DMOS transistor with a typical of 250mW assures high efficiency and a minimum dropout even at high output current level. The internal limiting current (latched function) of typical value of 2.5A protects the L6902D from accidental output short circuit avoiding dangerous loads damage.

If the temperature of the L6902D goes higher than a fixed internal threshold (150°C with 20°C hysteresis), the power stage is turned off.

Parameters:

Technical/Catalog Information	L6902D
Vendor	STMicroelectronics
Category	Integrated Circuits (ICs)
Type	Step-Down (Buck)
Number of Outputs	1
Voltage - Input	8 ~ 36 V
Voltage - Output	1.24 ~ 34 V
Current - Output	1A
Power - Output	700mW
Package / Case	8-SOIC (3.9mm Width)
Packaging	Tape & Reel (TR)
Internal Switch(s)	Yes
Synchronous	No
Rds (On)	-
Operating Temperature	-40°C ~ 150°C
Frequency - Switching	250kHz
Lead Free Status	Lead Free
RoHS Status	RoHS Compliant
Other Names	L6902D L6902D 497 3103 ND 4973103ND 497-3103