DESCRIPTION (CONTINUED)

VREF

R

AC

0.01 Ω

Q1 (ACFET)

SI4435

Q3(BATFET)

SI4435

Controlled by

HOST

P

P

ACN

ACP

ACDET

ACGOOD

SRSET

ACSET

VREF

GPIO

CELLS

CHGEN

VADJ

ADC

IADAPT

HOST

PVCC

HIDRV

PH

BTST

REGN

LODRV

PGND

SRP

SRN

P

PACK+

PACK–

SYSTEM

ADAPTER +

ADAPTER–

ACGOOD

AGND

bq24705

432 kΩ

1%

66.5 kΩ

1%

R1

R2

C4

C2

C5

C8

Q4

FDS6680A

C9

D1

BAT54

C10

BAT

ISYNSET

R6

30 kΩ

DPMDET

R4

Q2 (ACFET)

SI4435

Controlled by

HOST

C6

C15

0.1 µF

C1

2 Ω

R10

2.2 µF

0.1 µF

1 µF

10 kΩ

100 pF

C14

0.1 µF

0.1 µF

1 µF

R

SR

0.01 Ω

0.1 µF

10 µF

C7

10 µF

C12

10 µF

PowerPad

D2

BAT54

DAC

Q5

FDS6680A

L1

4.7 µH

C3

0.1µF

R3

10kΩ

C13

0.1 µF

C11

10 µF

bq24705

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

The bq24705 features Dynamic Power Management (DPM) and input power limiting. These features reduce

battery charge current when the input power limit is reached to avoid overloading the AC adapter when supplying

the load and the battery charger simultaneously. A highly-accurate current-sense amplifier enables precise

measurement of input current from the AC adapter to monitor the overall system power.

(1)

Pull-up rail could be either VREF or other system rail.

(2)

SRSET/ACSET could come from either DAC or resistor dividers.

(3)

Figure 2. Typical System Schematic, Voltage and Current Programmed by DAC

2

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Not Recommended for New Designs