LT1769 Constant-Current/Constant-Voltage 2A BatteryCharger with Input Current Limiting

The LT®1769 current mode PWM battery charger is a simple, efficient solution to fast charge modern rechargeable batteries including lithium-ion (Li-Ion), nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd) that require constant-current and/or constant-voltage charging. The internal switch is capable of delivering 2A** DC current (3A peak current). Charge current can be programmed by resistors or a DAC to within 5%. With 0.5% reference voltage accuracy, the LT1769 meets the critical constant-voltage charging requirement for Li-Ion cells.

A third control loop is provided to regulate the current drawn from the input AC adapter. This allows simultaneous operation of the equipment and battery charging without overloading the adapter. Charge current is reduced to keep the adapter current below specified levels.

The LT1769 can charge batteries ranging from 1V to 20V. Ground sensing of current is not required and the battery’s negative terminal can be tied directly to ground. A saturating switch running at 200kHz gives high charging efficiency and small inductor size. A blocking diode is not required between the chip and the battery because the chip goes into sleep mode and drains only 3µA when the wall adapter is unplugged

产品特点 Features

Simple Solution to Charge NiCd, NiMH and Lithium Rechargeable Batteries—Charging Current Programmed by Resistors or DAC
Adapter Current Limit Allows Maximum Possible Charging Current During System Use*
Precision 0.5% Accuracy for Voltage Mode Charging
High Efficiency Current Mode PWM with 3A Internal Switch
5% Charge Current Accuracy
Adjustable Undervoltage Lockout
Automatic Shutdown When AC Adapter is Removed
Low Reverse Battery Drain Current: 3µA
Current Sensing Can Be at Either Terminal of the Battery
Charging Current Soft Start
Shutdown Control
Available in 20-Lead Exposed Pad TSSOP and 28-Lead Narrow SSOP Packages

应用

Chargers for NiCd, NiMH, Lead-Acid, Lithium Rechargeable Batteries
Switching Regulators with Precision Current Limit

典型应用图

参数

LT1769 订购信息和价格参考Package Variations and Pricing

器件型号	封装	引脚	温度	价格 (以 1 ~ 99 片为批量)	价格 (以 1000 片为批量) *
LT1769CFE	TSSOP	20	C	$6.03	$5.10
LT1769CFE#PBF	TSSOP	20	C	$6.03	$5.10
LT1769CFE#TR	TSSOP	20	C		$5.22
LT1769CFE#TRPBF	TSSOP	20	C		$5.22
LT1769CGN	SSOP	28	C	$5.60	$4.95
LT1769CGN#PBF	SSOP	28	C	$5.60	$4.95
LT1769CGN#TR	SSOP	28	C		$5.05
LT1769CGN#TRPBF	SSOP	28	C		$5.05
LT1769IFE	TSSOP	20	I	$6.63	$5.60
LT1769IFE#PBF	TSSOP	20	I	$6.63	$5.60
LT1769IFE#TR	TSSOP	20	I		$5.72
LT1769IFE#TRPBF	TSSOP	20	I		$5.72
LT1769IGN	SSOP	28	I	$6.80	$6.00
LT1769IGN#PBF	SSOP	28	I	$6.80	$6.00
LT1769IGN#TR	SSOP	28	I		$6.10
LT1769IGN#TRPBF	SSOP	28	I		$6.10

LT1769 数据手册及相关资料下载

数据手册(英文) : LT1769 - Constant-Current/Constant-Voltage 2A Battery Charger with Input Current Limiting.PDF
设计要点 (英文) : DN242 - Li-Ion Charge Termination IC Interfaces with PWM Switchers.PDF
可靠性数据 : R324 Reliability Data .PDF