PSC1534 Datasheet, PDF (1/8 Pages) Agere Systems – Lithium-Ion Linear Battery Charger

Preliminary Data Sheet
April 2003
PSC1534 Lithium-Ion Linear Battery Charger
Features
Applications
s Low external component count and small footprint
s Charge termination indication and manual shut-
down using PROG pin
s Programmable charge current: 200 mA to 800 mA
s 4.1 V or 4.2 V preset voltages
s Automatic trickle charging at IPROG/10 for heavily
discharged batteries requires no additional exter-
nal components
s Very low quiescent battery current during shut-
down and standby (charger removed)
s Charger undervoltage lockout and battery over-
voltage lockout
s Overcurrent/overtemperature protection
s Low-profile (1 mm) SOT-23 package
s Any application that requires a compact, low-cost
solution for Li-Ion battery charging
Typical Application
VIN
5V
1 µF
3 _VCC
ISENSE ¹
2 ^PSC1534 6
GND DRIVE
FMMT549
10 kΩ
To A/D
4 _PROG
RPROG
3 kΩ
BAT ⁵
10 µF
IBAT = 500 mA
+ _SINGLE
Li-Ion
BATTERY
Figure 1. 500 mA Li-Ion Battery Charger
Description
The PSC1534 is a constant-current/constant-voltage
Li-Ion battery charger controller that is functionally
equivalent and performance equivalent to the
LTC^®1734. As an enhancement, the PSC1534 also
includes automatic detection and trickle charging of
deeply discharged batteries (VBAT <2.42 V).
The PSC1534 allows charge current programming
using a single external resistor, RPROG. The voltage
on the PROG pin is proportional to the charging cur-
rent at the ISENSE pin, allowing the user to use an
external A/D to monitor charging progress. A low bat-
tery drain (BAT pin) manual shutdown state can be
forced by floating the PROG pin. When the input sup-
ply (VIN) is removed, the PSC1534 enters a very low-
current sleep mode, during which BAT input supply
current is <1 µA.
5V
VBAT
4V
3V
2V
1.5 V
1V
CONSTANT CONSTANT
CURRENT VOLTAGE
VPROG
0V
CHARGING
BEGINS
CHARGING
COMPLETE
Figure 2. PROG Pin Indicates Charge Status