BQ24600_1 Datasheet, PDF (11/31 Pages) Texas Instruments – Stand-Alone Synchronous Switch-Mode Li-Ion or Li-Polymer Battery Charger with Low Iq

bq24600
www.ti.com
SLUS891 – FEBRUARY 2010
PIN
NO. NAME
1 VCC
2 CE
3 STAT
4 TS
5 PG
6 VREF
7 ISET
8 VFB
9 SRN
10 SRP
11 GND
12 REGN
13 LODRV
14 PH
15 HIDRV
16 BTST
PowerPad
PIN FUNCTIONS
FUNCTION DESCRIPTION
IC power positive supply. Connect, through a 10 Ω resistor to the common-source (diode-OR) point: source of
high-side P-channel MOSFET and source of reverse-blocking power P-channel MOSFET. Or connect through a 10 Ω
resistor to the cathode of the input diode. Place a 1-mF ceramic capacitor from VCC to GND pin close to the IC.
Charge-enable active-HIGH logic input. HI enables charge. LO disables charge. It has an internal 1MΩ pull-down
resistor.
Open-drain charge status pin to indicate various charger operation (See Table 3)
Temperature qualification voltage input for battery pack negative temperature coefficient thermistor. Program the hot
and cold temperature window with a resistor divider from VREF to TS to GND.
Open-drain power-good status output. The transistor turns on when a valid VCC is detected. It is turned off in the
sleep mode. PG can be used to drive a LED or communicate with a host processor. It can be used to drive ACFET
and BATFET.
3.3V regulated voltage output. Place a 1-mF ceramic capacitor from VREF to GND pin close to the IC. This voltage
could be used for programming of voltage and current regulation and for programming the TS threshold.
Charge current set input. The voltage of ISET pin programs the charge current regulation, pre-charge current and
termination current set-point.
Output voltage analog feedback adjustment. Connect the output of a resistive voltage divider from the battery
terminals to this node to adjust the output battery regulation voltage.
Charge current sense resistor, negative input. A 0.1-mF ceramic capacitor is placed from SRN to SRP to provide
differential-mode filtering. An optional 0.1-mF ceramic capacitor is placed from SRN pin to GND for common-mode
filtering.
Charge current sense resistor, positive input. A 0.1-mF ceramic capacitor is placed from SRN to SRP to provide
differential-mode filtering. A 0.1-mF ceramic capacitor is placed from SRP pin to GND for common-mode filtering.
Low-current sensitive analog/digital ground. On PCB layout, connect with PowerPad underneath the IC.
PWM low side driver positive 6V supply output. Connect a 1-mF ceramic capacitor from REGN to PGND pin, close to
the IC. Use for low side driver and high-side driver bootstrap voltage by connecting a small signal Schottky diode from
REGN to BTST.
PWM low side driver output. Connect to the gate of the low-side power MOSFET with a short trace.
PWM high side driver negative supply. Connect to the Phase switching node (junction of the low-side power MOSFET
drain, high-side power MOSFET source, and output inductor). Connect the 0.1mF bootstrap capacitor from PH to
BTST.
PWM high side driver output. Connect to the gate of the high-side power MOSFET with a short trace.
PWM high side driver negative supply. Connect to the Phase switching node (junction of the low-side power MOSFET
drain, high-side power MOSFET source, and output inductor). Connect the 0.1mF bootstrap capacitor from SW to
BTST
Exposed pad beneath the IC. Always solder PowerPad to the board, and have vias on the PowerPad plane
star-connecting to GND and ground plane for high-current power converter. It also serves as a thermal pad to
dissipate the heat.
Copyright © 2010, Texas Instruments Incorporated
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