MAX1909 Maxim Integrated Products, MAX1909 Datasheet - Page 13

• Manufacturer Part Number: MAX1909
• Description: (MAX8725 / MAX1909) Multichemistry Battery Charger
• Manufacturer: Maxim Integrated Products

Multichemistry Battery Chargers with Automatic
PIN
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
1
2
3
4
5
6
7
8
9
PKPRES
NAME
ACOK
PGND
MODE
DLOV
CSSN
DCIN
VCTL
BATT
CSSP
ACIN
CSIN
DHIV
GND
GND
CSIP
LDO
ICTL
CCV
CCS
DLO
IINP
CLS
SRC
PDS
PDL
REF
CCI
DHI
______________________________________________________________________________________
DC Supply Voltage Input. Bypass DCIN with a 1µF capacitor to power ground.
D evi ce P ow er S up p l y. Outp ut of the 5.4V l i near r eg ul ator sup p l i ed fr om D C IN . Byp ass w i th a 1µF cap aci tor .
AC Detect Input. This uncommitted comparator input can be used to detect the presence of the charger’s
power source. The comparator’s open-drain output is the ACOK signal.
4.2235V Voltage Reference. Bypass with a 1µF capacitor to GND.
MAX1909: Ground this pin
MAX8725: Pull PKPRES high to disable charging. Used for detecting presence of battery pack.
AC Detect Output. High-voltage open-drain output is high impedance when ACIN is greater than 2.048V. The
ACOK output remains a high impedance when the MAX1909/MAX8725 are powered down.
Trilevel Input for Setting Number of Cells and Asserting the Conditioning Mode:
MODE = GND; asserts conditioning mode.
MODE = float; charge with 3 times the cell voltage programmed at VCTL.
MODE = LDO; charge with 4 times the cell voltage programmed at VCTL.
Input Current Monitor Output. The current delivered at the IINP output is a scaled-down replica of the system
load current plus the input-referred charge current sensed across CSSP and CSSN inputs. The
transconductance of (CSSP - CSSN) to IINP is 3mA/V.
Source Current-Limit Input. Voltage input for setting the current limit of the input source.
Input for Setting Maximum Output Current
Input for Setting Maximum Output Voltage
Output Current-Regulation Loop-Compensation Point. Connect 0.01µF to GND.
Voltage-Regulation Loop-Compensation Point. Connect 10k in series with 0.1µF to GND.
Input Current-Regulation Loop-Compensation Point. Use 0.01µF to GND.
Analog Ground
Battery Voltage Feedback Input
Output Current-Sense Negative Input
Output Current-Sense Positive Input. Connect a current-sense resistor from CSIP to CSIN.
Power Ground
Low-Side Power-MOSFET Driver Output. Connect to low-side NMOS gate. When the MAX1909/MAX8725 are
shut down, the DLO output is LOW.
Low-Side Driver Supply. Bypass with a 1µF capacitor to ground.
High-Side Driver Supply. Bypass with a 0.1µF capacitor to SRC.
High-Side Power-MOSFET Driver Output. Connect to high-side PMOS gate. When the MAX1909/MAX8725 are
shut down, the DHI output is HIGH.
Source Connection for Driver for PDS/PDL Switches. Bypass SRC to power ground with a 1µF capacitor.
Input Current Sense for Charger (Negative Input)
Input Current Sense for Charger (Positive Input). Connect a current-sense resistor from CSSP to CSSN.
Power-Source PMOS Switch Driver Output. When the MAX1909/MAX8725 are powered down, the PDS output
is pulled to SRC through an internal 1M resistor.
System-Load PMOS Switch Driver Output. When the MAX1909/MAX8725 are powered down, the PDL output
is pulled to ground through an internal 100k resistor.
System Power Selector
FUNCTION
Pin Description
13