mc33348d ON Semiconductor, mc33348d Datasheet - Page 6

• Manufacturer Part Number: mc33348d
• Description: Lithium Battery Protection Circuit For One Cell Smart Battery Packs
• Manufacturer: ON Semiconductor

Pin
6
1
2
3
4
5
6
7
8
Cell Voltage
Test
Ground
Discharge Gate Drive
Output
Charge Gate Drive
Common/Discharge
Current Limit
Charge Gate Drive
Output
V CC
Charge Pump Output
Symbol
Cell
Components C I is mandatory. Refer to the Battery Pack Application text.
This input is connected to the positive terminal of the cell for voltage monitoring. Internally, the Cell
Voltage Sample Switch applies this voltage to a resistor divider where it is compared by the Cell Voltage
Detector to an internal reference.
This pin is normally not connected and is used in testing the protection IC. An active low at this input
resets the internal logic and turns on both MOSFET switches. Upon release, the logic becomes active and
the cell voltage is sampled within 1.0 ms.
This is the protection IC ground and all voltage ratings are with respect to this pin.
This output connects to the gate of discharge switch Q2 allowing it to enable or disable battery pack
discharging.
This is a multifunction pin that is used to monitor cell discharge current and to provide a gate turn–off
path for charge switch Q1. A discharge current limit fault is set when the battery pack load causes the
combined voltage drop of charge switch Q1 and discharge switch Q2 to exceed the discharge current limit
threshold voltage, V th(dschg) , with respect to Pin 3.
This output connects to the gate of charge switch Q1 allowing it to enable or disable battery pack
charging.
This pin is the positive supply voltage for the protection IC.
This is the charge pump output. A reservoir capacitor is connected from this pin to ground.
Voltage
Ground
Test
Cell
Charge Pump
1
2
3
Figure 7. One Cell Smart Battery Pack
Output
Charge Pump
0.01
Oscillator
C O
PIN FUNCTION DESCRIPTION
MC33348
Cell Voltage
2.0 k
Sample
En
Switch
8
Switch Q2
Discharge
Gate Drive
Discharge
Ck
Ck
Output
MC33348
Charge/Discharge
4
Gate Drivers
Gate Drive
Control Logic
Cell Voltage
Over/Under
1.0 M
Over/Under
Data Latch
Reference
Detector
Charge
Output
10
&
&
Description
6
Charge
Switch
Q1
5 Charge
Enable
Sense
Overcurrent
Discharge
Detector
Gate Drive
Common/
Discharge
Current Limit
R1
R2
R3
MOTOROLA ANALOG IC DEVICE DATA
5.1 k
7
V CC
0.1
C I