MAX846A Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Cost-Saving Multichemistry Battery-Charger System

19-1121; Rev 0; 9/96
EVAALVUAAILTAIOBNLEKIT
Cost-Saving Multichemistry
Battery-Charger System
_______________General Description
The MAX846A is a cost-saving multichemistry battery-
charger system that comes in a space-saving 16-pin
QSOP. This integrated system allows different battery
chemistries (Li-Ion, NiMH or NiCd cells) to be charged
using one circuit.
In its simplest application, the MAX846A is a stand-
alone, current-limited float voltage source that charges
Li-Ion cells. It can also be paired up with a low-cost
microcontroller (µC) to build a universal charger capa-
ble of charging Li-Ion, NiMH, and NiCd cells.
An internal 0.5%-accurate reference allows safe charg-
ing of Li-Ion cells that require tight voltage accuracy.
The voltage- and current-regulation loops used to con-
trol a low-cost external PNP transistor (or P-channel
MOSFET) are independent of each other, allowing more
flexibility in the charging algorithms.
The MAX846A has a built-in 1%, 3.3V, 20mA linear regu-
lator capable of powering the µC and providing a refer-
ence for the µC’s analog-to-digital converters. An
on-board reset notifies the controller upon any unex-
pected loss of power. The µC can be inexpensive, since
its only functions are to monitor the voltage and current
and to change the charging algorithms.
________________________Applications
Li-Ion Battery Packs
Desktop Cradle Chargers
Li-Ion/NiMH/NiCd Multichemistry Battery
Chargers
Cellular Phones
Notebook Computers
Hand-Held Instruments
__________________Pin Configuration
TOP VIEW
DCIN 1
VL 2
CCI 3
GND 4
CCV 5
VSET 6
ISET 7
OFFV 8
MAX846A
16 DRV
15 PGND
14 CS-
13 CS+
12 BATT
11 ON
10 CELL2
9 PWROK
QSOP
____________________________Features
o Multichemistry Charger System (Li-Ion, NiMH, NiCd)
o Independent Voltage and Current Loops
o ±0.5% Internal Reference for Li-Ion Cells
o Lowers Cost:
—Stands Alone or Uses Low-Cost µC
—Built-In 1% Linear Regulator Powers µC
—Linear Regulator Provides Reference to µC ADCs
—Built-In µC Reset
—Controls Low-Cost External PNP Transistor or
P-Channel MOSFET
o Space-Saving 16-Pin QSOP
o Charging-Current-Monitor Output
o <1µA Battery Drain when Off
______________Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
MAX846AC/D
0°C to +70°C
Dice*
MAX846AEEE
-40°C to +85°C
16 QSOP
*Dice are tested at T_A = +25°C only. Contact factory for details.
__________Typical Operating Circuit
3.5V
TO
20V
DRV
CS-
BATT
CS+
DCIN
MAX846A
ISET
VL
CELL2
CCV
GND
CCI
PGND
PWROK
ON
Li-ION
BATTERY
________________________________________________________________ Maxim Integrated Products 1
For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone]