Rainbow Electronics DS2778 - Manual (Page 7)

DS2775/DS2776/DS2777/DS2778
2-Cell, Stand-Alone, Li+ Fuel-Gauge IC with
Protector and Optional SHA-1 Authentication
_______________________________________________________________________________________ 7
CURRENT MEASUREMENT
ACCURACY
DS2775/6/7/8 toc07
V
SNS
(mV)
ACCURACY (
μ
V)
0.048 0.028 0.008 -0.012 -0.032
-75
-25
25
75
125
-125
-0.052
+70 °C
-20 °C
+25 °C
I RC vs. V DD
DS2775/6/7/8 toc08
V DD (V)
I RC
(mA)
5 4 3 2 1
1
2
3
4
5
6
7
0
0 6
1k Ω RESISTOR FROM PLS TO PK+
CURRENT MEASUREMENT OFFSET
vs. TEMPERATURE
DS2775/6/7/8 toc09
TEMPERATURE ( °C)
LSB (1.5625
μ
V)
60 40 20 0
-4
-3
-2
-1
0
1
2
-5
-20
Typical Operating Characteristics (continued)
(T A = +25°C, unless otherwise noted.)
Pin Description
PIN NAME FUNCTION
1 CC Charge Control. Charge FET control output.
2 V DD Chip-Supply Input. Bypass with 0.1μF to V SS .
3 DC Discharge Control. Discharge FET control output.
4 V IN2
Battery Voltage Sense Input 2. Connect to highest voltage potential positive cell terminal through
decoupling network.
5 V IN1
Battery Voltage Sense Input 1. Connect to lowest voltage potential positive cell terminal through
decoupling network.
6 VB Regulated Operating Voltage. Bypass with 0.1μF to V SS .
7 V SS Device Ground. Chip ground and battery-side sense resistor input.
8 SNS Sense Resistor Connection. Pack-side sense resistor sense input.
9 PIO Programmable I/O. Can be configured as wake input.
10 PLS
Pack Plus Terminal Sense Input. Used to detect the removal of short-circuit, discharge overcurrent, and
charge overcurrent conditions.
11 SDA/DQ
Data Input/Output. Serial data I/O, includes weak pulldown to detect system disconnect and can be
configured as wake input for 1-Wire devices.
12 SCL/OVD
Serial Clock Input/Overdrive Select. Communication clock for 2-wire devices/overdrive select pin for
1-Wire devices.
13 SRC Protection MOSFET Source Connection. Used as a reference for the charge pump.
14 CP Charge Pump Output. Generates gate drive voltage for protection FETs. Bypass with 0.47μF to SRC.
— EP Exposed Pad. Connect to ground or no connection.