BQ24700 Datasheet, PDF (10/29 Pages) Texas Instruments – NOTEBOOK PC BATTERY CHARGE CONTROLLER AND SELECTOR WITH DPM

bq24700, bq24701
ą
NOTEBOOK PC BATTERY CHARGE CONTROLLER
AND SELECTOR WITH DPM
SLUS452B – APRIL 2001 – REVISED NOVEMBER 2002
Terminal Functions
TERMINAL
NAME NO.
ACDET
1
ACDRV
24
ACN
11
ACP
12
ACPRES
2
ACSEL
3
ACSET
6
ALARM
19
BATDEP
4
BATDRV
23
BATP
13
BATSET
9
COMP
10
ENABLE
8
GND
17
IBAT
14
PWM
21
SRN
15
SRP
16
SRSET
5
VCC
22
VHSP
20
VREF
7
VS
18
I/O
DESCRIPTION
I AC or adapter power detection
O AC or adapter power source selection output
I Negative differential input
I Positive differential input
O AC power indicator
I AC adapter power select
I Adapter current programming voltage
O Depleted battery alarm output
I Depleted battery level
O Battery power source select output
I Battery charge regulation voltage measurement input to the battery-voltage gm amplifier
I External override to an internal 0.5% precision reference
O Inverting input to the PWM comparator
I Charge enable
O Supply return and ground reference
O Battery current differential amplifier output
O Gate drive output
I Negative differential battery current sense amplifier input
I Positive differential battery current sense amplifier input
I Battery charge current programming voltage
I Operational supply voltage
O Voltage source to drive gates of the external MOSFETs
O Precision voltage 5-V, ±0.6% reference
I System (load) voltage input pin
pin assignments
ACDET: AC or adapter power detection. This input pin is used to determine the presence of the ac adapter.
When the voltage level on the ACDET pin is less than 1.20 V, the bq24700/bq24701 is in sleep mode, the PWM
control is disabled, the BATDRV is driven low and the ACDRV is driven high. This feature can be used to
automatically select battery as the system’s power source.
ACDRV: AC or adapter power source select output. This pin drives an external P-channel MOSFET used to
switch to the ac wall-adapter as the system’s power source. When the ACSEL pin is high while the voltage on
the ACDET pin is greater than 1.20 V, the output ACDRV pin is driven low (V_HSP). This pin is driven high (V_CC)
when the ACDET is less than 1.20 V.
ACN, ACP: Negative and positive differential inputs, respectively for ac-to-dc adapter current sense resistor.
ACPRES: This open-drain output pin is used to indicate the presence of ac power. A logic high indicates there
is a valid ac input. A low indicates the loss of ac power. ACPRES is high when the voltage level on the ACDET
pin is greater than 1.20 V.
ACSEL: AC adapter power select. This input selects either the ac adapter or the battery as the power source.
A logic high selects ac power, while a logic low selects the battery.
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