“loose” cells. Temperature, voltage, and charge time
are monitored to provide proper fast-charging control
algorithms for nickel metal hydride (NiMH) batteries.
Battery tests are included to detect defective or
inappropriate cells such as alkaline primary batteries.
The DS2711/DS2712 support series and parallel
topologies, with independent monitoring and control of
each cell. Charging of NiCd chemistry cells is also
supported.
PIN CONFIGURATION
CC1
CC2
LED1
VSS
LED2
CSOUT
VN1
VN0
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
APPLICATIONS
Desktop/Stand-Alone Chargers (AAA/AA)
Digital Still Cameras
Music Players
Games
Toys
VP2
VP1
THM2
THM1
VDD
TMR
CTST
DMSEL
SO (150 mils)
TSSOP (4.4mm)
PIN DESCRIPTION
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
NAME
CC1
CC2
LED1
V
SS
LED2
CSOUT
VN1
VN0
DMSEL
CTST
TMR
V
DD
THM1
THM2
VP1
VP2
FUNCTION
Cell 1 Charge-Control Output
Cell 2 Charge-Control Output
Cell 1 Status
Ground Reference and Chip-
Supply Return
Cell 2 Status, Mode-Select Input
Current-Sense Output
Current-Sense + Input
Current-Sense - Input
Display-Mode Select
Cell Test Threshold Set
Charge Timer Set
Chip-Supply Input (4.0V to 5.5V)
Cell 1 Thermistor Input
Cell 2 Thermistor Input
Cell 1 Positive-Terminal Sense
Input
Cell 2 Positive-Terminal Sense
Input
FEATURES
Charge 1 or 2 NiMH Cells
Detect and Avoid Charging Alkaline Cells
Precharge Deeply Depleted Cells
Fast Charge NiMH with -∆V Termination
Sensitivity of 2mV (typ)
Monitor Voltage, Temperature, and Time for
Safety and Secondary Termination
Regulate Charge Current:
Linear Control (DS2711)
Switch-Mode Control (DS2712)
Drive pMOS or pnp-Type Pass Element or
Switch, or an Optocoupler
Compatible with Popular Optocouplers and
Integrated Primary-Side PWM Controllers
Small 16-Pin SO or TSSOP Packages
1 of 15
DS2711/DS2712: Loose-Cell NiMH Chargers
ABSOLUTE MAXIMUM RATINGS
Voltage Range on All Pins Relative to V
SS
……………………………………………………………………-0.3V to +6V
Voltage Range on DMSEL……………………………………………….……………………………………….V
DD
+ 0.3V
Continuous Sink Current CC1, CC2, LED1, LED2, and CSOUT………………………………............................20mA
Operating Temperature Range………………………………………………………………………………-40°C to +85°C
Storage Temperature Range……………………………………………………………………………….-55°C to +125°C
Lead Temperature (soldering, 10s) ................................................................................................................. +300°C