M61043FP
3-Battery Version, Reset Pin
REJ03F0065-0100Z
Rev.1.0
Sep.19.2003
Description
The M61043FP is an semiconductor IC device developed for smart battery packs. It incorporates all the analog circuitry
required by smart batteries in a single chip. When used in conjunction with a microprocessor, it allows the
implementation of a variety of functions, such as battery capacity detection, through the addition of minimal peripheral
devices and is ideal for smart battery system (SBS) battery packs.
The M61043FP also has an on-chip overcurrent detect circuit so that the FET for controlling battery charging and
discharging is protected regardless of the processing speed of the microprocessor.
The microprocessor can change the amplifier gain of the charge/discharge current detect circuit, so battery capacity
detection accuracy is increased. In addition, the M61043FP incorporates a linear regulator that allows it to function as
the power supply for the microprocessor, thereby simplifying power supply block design.
Features
•
•
•
•
•
•
On-chip high-gain op-amp for monitoring charge and discharge current.
On-chip overcurrent detect circuit to protect FET.
Charge/discharge FET can be controlled from microprocessor.
Power-save function for reducing current consumption.
5.2 V operation to reduce microprocessor current consumption.
High-voltage device (absolute maximum rating: 33 V).
Application
Smart battery system (SBS) battery packs
Pin Connection Diagram (Top View)
VCC
RESET
VIN_1
VIN_2
VIN_3
VIN_12
DFOUT
CFOUT
1
2
16 VREG
15 DI
M61043FP
3
4
5
6
7
8
14 CK
13 CS
12 CIN
11 Analog_out
10 VIN_11
9
GND
Package: 16P-TSSOP
Rev.1.0, Sep.19.2003, page 1 of 34
M61043FP
Block Diagram
CFOUT
VCC
VREG
Series
regulator
Regulator
On/off control
Power-down
circuit
Battery
voltage
detect
circuit
Charge/discharge current
detect circuit
FET control
circuit
Overcurrent
detect circuit
Delay
circuit
DFOUT
CIN
VIN_12
RESET
CK
DI
CS
Serial/parallel
converter
circuit
VIN_1
VIN_2
Gain switcher circuit
Analog
_OUT
Output
selector
Shift
voltage
adjustor
Battery 1-3
analog output
VIN_3
VIN_11
GND
Rev.1.0, Sep.19.2003, page 2 of 34
M61043FP
Pin Function
Table 1
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Symbol
Vcc
RESET
VIN_1
VIN_2
VIN_3
VIN_12
DFOUT
CFOUT
GND
VIN_11
Analog_OUT
CIN
CS
Function
The chip’s power supply pin. Power is supplied by the charger or the battery.
Output pin for microprocessor reset signal.
Positive input pin for lithium ion battery 1.
Negative input pin for lithium ion battery 1. Positive input pin for lithium ion battery 2.
Negative input pin for lithium ion battery 2. Positive input pin for lithium ion battery 3.
Charger connect monitor pin. Detects changes from power-down status.
Output pin for discharge FET on/off signals. Also turns off when overcurrent detected.
Output pin for charge FET on/off signals.
Ground pin. Negative input pin for lithium ion battery 3. Connected to charge/discharge
current sensor resistor.
Charge/discharge current monitor pin. Connected to charge/discharge current sensor
resistor.
Output pin for analog signals.
Capacity connection pin for setting overcurrent prevention delay time.
When this pin is low level, data input is accepted and data can be stored in a 6-bit shift
register. At the rising edge from low to high the value in the 6-bit shift register is
latched.
Shift clock input pin. At the rising edge to high the input signal from the DI pin is input to
the 6-bit shift register.
Shift data input pin. Serial data with a data length of 6 bits may be input via this pin.
Power supply pin for microprocessor. Power can be shut off using a signal from the
microprocessor.
14
15
16
CK
DI
Vreg
Operation
The M61043FP is an semiconductor IC device developed for smart battery packs. It is ideal for smart battery system
(SBS) battery packs that consist of four lithium ion batteries connected in series. A high-voltage device, it is suitable
for use with a wide variety of charger systems.
It incorporates all the analog circuitry required by smart batteries in a single chip. When used in conjunction with a
microprocessor, it allows the implementation of a variety of functions, such as battery capacity detection, through the
addition of minimal peripheral devices. The functions of the M61043FP are described below.
1. Battery Voltage Detect Circuit
The M61043FP can output the voltage levels of the batteries connected in series via the Analog_out pin. An on-chip
buffer amplifier monitors the pin voltages of the batteries. Offset voltage correction using adjustment by the
microprocessor is also supported. The M61043FP is configured to detect the battery voltage using a microprocessor
driven using a power supply voltage of 5.2 V.
2. Charge/Discharge Current Detect Circuit
SBS requires a function for monitoring the battery capacity. The M61043FP uses an on-chip amplifier to monitor
battery capacity based on a drop in the voltage of an external sensor resistor. In this way, the charge/discharge current is
converted into a voltage.
The voltage amplification ratio can be adjusted from the microprocessor. In addition, the current output shift voltage
can be adjusted from the microprocessor, widening the allowable dynamic range of the A/D converter.
Rev.1.0, Sep.19.2003, page 3 of 34
M61043FP
3. Overcurrent Detect Circuit
The M61043FP has an on-chip overcurrent detect circuit. If an excessive current flows from the lithium ion batteries,
the discharge control FET is shut off after a set delay time, halting discharge. This makes the battery pack safer. The
delay time can be set using an external capacitor. It is possible to determine the overcurrent detect status by monitoring
the CIN pin. The overcurrent detect circuit provides protection regardless of the processing speed of the microprocessor.
4. Series Regulator
The M61043FP has an on-chip low-dropout series regulator. It can be used as the power supply for the microprocessor,
thereby simplifying power supply block design.
VCC
VREF1
-
+
M1
Vreg
ON/OFF
R
1
R
2
From serial/parallel converter circuit
Figure 3 Series Regulator
5. Reset Circuit
The reset circuit of the M61041FP monitors the voltage of the Vreg pin. If the power supply voltage of the
microprocessor drops the reset circuit operates, preventing microprocessor runaway. Microprocessor runaway is
avoided because the microprocessor is reset if the battery pack left standing and the battery voltage is allowed to drop.
This enhances the safety of battery packs that are left unused.
In addition, reset circuit monitors the voltage of the Vreg pin when the battery pack is connected to the charger,
ensuring that a reset will be applied if the voltage supplied to the microprocessor becomes excessively small. This helps
to guarantee reliable operation.
6. Power-Save Function
The M61043FP is equipped with a power-save function.
When the battery voltage is being monitored a portion of the charge/discharge current monitor circuit automatically
stops operating, and when the charge/discharge current is being monitored the battery voltage monitor circuit
automatically stops operating. This helps prevent unnecessary power consumption. In addition, current consumption is
further reduced by setting the analog output selector to ground potential output when in the standby mode.
Transition to Power-Down Mode
When the microprocessor determines that the battery voltage has dropped it sends a power-down instruction via the
interface circuit. When it receives the instruction, the M61043FP’s DFOUT pin switches to high voltage. In addition,
the VIN_12 pin is pulled down to low level by an internal resistor. When the VIN_12 pin goes to low potential after
reception of the power-down instruction, output from the series regulator stops, switching the M61043FP into power-
down mode.
Rev.1.0, Sep.19.2003, page 4 of 34
M61043FP
At this point the operation of the circuitry is completely halted. In this status CFOUT is high level and DFOUT is high
level (external charge/discharge prohibited status). The maximum current consumption of the M61043FP is 1.0 µA in
order to prevent any further drop in the battery voltage.
DFOUT
VIN_12
VCC
CFOUT
Ground level after
excess discharge
Series
regulator
Control signals from
interface circuit
VIN_1
Vreg
M61043FP-D70Z
RESET
Regulator
On/off control
Internal reset
circuit
Serial/parallel
converter circuit
CK
DI
CS
Figure 4 Operation After Excess Discharge Detection
Cancellation of Power-Down Mode
If the battery pack is connected to a charger when the M61043FP is in the power-down mode (VIN_12 becomes high
level), the series regulator immediately begins to operate. The power-down mode is canceled, and once again the
M61043FP is ready to receive instructions from the microprocessor.
Absolute Maximum Ratings
Table 2
Item
Absolute maximum rating
Power supply voltage
Allowable loss
Ambient operating temperature
Storage temperature
Symbol
Vabs
Vcc
PD
Topr
Tstg
Rated Value
33
30
500
-20 to +85
-40 to +125
Unit
V
V
mW
°C
°C
Conditions
Rev.1.0, Sep.19.2003, page 5 of 34
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