Document
19-5826; Rev 4/11
GENERAL DESCRIPTION
The DS2711 and DS2712 are ideal for in-system or stand-alone charging of 1 or 2 AA or AAA NiMH “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.
APPLICATIONS
Desktop/Stand-Alone Chargers (AAA/AA)
Digital Still Cameras
Music Players
Games
Toys
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
DS2711/DS2712 Loose-Cell NiMH Chargers
PIN CONFIGURATION
CC1 CC2 LED1 VSS LED2 CSOUT VN1 VN0
1 2 3 4 5 6 7 8
16 VP2 15 VP1 14 THM2 13 THM1 12 VDD 11 TMR 10 CTST 9 DMSEL
SO (150 mils) TSSOP (4.4mm)
PIN DESCRIPTION
PIN NAME
FUNCTION
1 CC1 Cell 1 Charge-Control Output
2 CC2 Cell 2 Charge-Control Output
3 LED1 Cell 1 Status
4
VSS
Ground Reference and ChipSupply Return
5 LED2 Cell 2 Status, Mode-Select Input
6 CSOUT Current-Sense Output
7 VN1 Current-Sense + Input
8 VN0 Current-Sense - Input
9 DMSEL Display-Mode Select
10 CTST Cell Test Threshold Set
11 TMR Charge Timer Set
12 VDD Chip-Supply Input (4.0V to 5.5V)
13 THM1 Cell 1 Thermistor Input
14 THM2 Cell 2 Thermistor Input
15
VP1
Cell 1 Positive-Terminal Sense Input
16
VP2
Cell 2 Positive-Terminal Sense Input
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DS2711/DS2712: Loose-Cell NiMH Chargers
ABSOLUTE MAXIMUM RATINGS
Voltage Range on All Pins Relative to VSS……………………………………………………………………-0.3V to +6V Voltage Range on DMSEL……………………………………………….……………………………………….VDD + 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 Soldering Temperature (reflow)
Lead(Pb)-free ............................................................................................................................................ +260°C Containing lead(Pb)................................................................................................................................... +240°C
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.
RECOMMENDED DC OPERATING CONDITIONS
(4.0V ≤ VDD ≤ 5.5V, TA = -20°C to +70°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP MAX UNITS
Supply Voltage
VDD (Note 1)
4.0 5.5 V
Input Voltage Range
LED2, DMSEL
-0.3
+5.5
V
DC ELECTRICAL CHARACTERISTICS
(4.0V ≤ VDD ≤ 5.5V, TA = -20°C to +70°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP MAX UNITS
Supply Current, VDD
IDD Operating mode
250 500
µA
UVLO Threshold
UVLO Hysteresis
Output-Voltage Low, CC1, CC2, LED1, LED2 Output-Voltage Low, CSOUT Leakage Current, CC1, CC2, LED1, LED2, CSOUT Threshold Voltage, -∆V Termination Mode Test Current, DMSEL, LED2 Input Logic-High, DMSEL, LED2 Input Logic-Low, DMSEL, LED2
Input Leakage Current, DMSEL
Threshold Voltage, Cell Test Threshold Voltage, Cell Voltage Low Threshold Voltage, Cell Voltage Max1 Threshold Voltage, Cell Voltage Max2
Threshold Voltage Delta
VUVLO VUHYS VOL1 VOL2
ILKG
V-∆V IMTST VIH VIL
IIL1
VCTST VBAT-LOW VBAT-MAX1 VBAT-MAX2 VBAT-MAXΔ
VDD rising (Note 1)
VDD falling from above VUVLO VDD = 5.0V, IOL = 20mA (Note 1) VDD = 5.0V, IOL = 20mA (Note 1)
VDD = 5.0V, Output inactive
After tTHO
(Notes 2, 3)
(Note 1)
(Note 1)
After power-up mode select, DMSEL = VDD or VSS
RCTST = 80kΩ
CC1 = CC2 = high-Z (Note 4) CC1 = CC2 = high-Z (Note 4) CC1, CC2 active (Note 4) VBAT-MAX2 - VBAT-MAX1 (Note 5)
3.5 3.9
40
1.0
0.75
1.25
-1 +1
1.0
VDD 0.2
2.0 5
3.0 15
0.2
-1 +1
85 0.9 1.55 1.64 90
100 1.0 1.65 1.75 100
115 1.1 1.75 1.86 110
V mV V V
µA
mV µA V V
µA
mV V V V mV
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DS2711/DS2712: Loose-Cell NiMH Chargers
PARAMETER Threshold Voltage, Thermistor - Min Threshold Voltage, Thermistor - Max Threshold Voltage, Thermistor - Stop Threshold Current, TMR Pin Suspend Presence.