Datasheet

14 Maxim Integrated
1.2A Switch-Mode Li+ Chargers with ±22V Input
Rating and JEITA Battery Temperature Monitoring
MAX8900A/MAX8900B/MAX8900C
Pin Description (continued)
PIN NAME FUNCTION
C3–C6 INBP
Power Input Bypass. Connect all INBP pins together externally. Bypass INBP to PGND with a 0.47FF
ceramic capacitor.
D1 STAT1
Status Output 1. STAT1 is an open-drain output that has a 30V absolute maximum rating and a typical
internal pulldown resistance of 25I. For the MAX8900A, STAT1 and STAT2 indicate different states
as shown in Table 4. For the MAX8900B/MAX8900C, STAT1, STAT2, and STAT3 indicate different
operating states of the MAX8900_ as shown in Table 3.
D2 STAT3
Status Output 3. STAT3 is an open-drain output that is a 6V absolute maximum rating and a typical
pulldown resistance of 10I. For the MAX8900A, STAT1 and STAT2 indicate different states as shown
in Table 4. For the MAX8900B/MAX8900C, STAT1, STAT2, and STAT3 indicate different operating
states of the MAX8900_ as shown in Table 3.
D3–D6 IN
Power Input. IN is capable of delivering 1.2A to the battery and/or system. Connect all IN pins
together externally. Bypass IN to PGND with a 0.47FF ceramic capacitor.
E1 DNI
Done/Prequalification Program Input. DNI is a dual function pin that sets both the done current
threshold and the prequalification charge rate. Connect a resistor from DNI to GND to set the
threshold between 10mA and 200mA. DNI is pulled to GND during shutdown.
E2 SETI
Fast-Charge Current Program Input. Connect a resistor from SETI to GND to set the fast-charge
current from 0.05A to 1.2A. SETI is pulled to GND during shutdown.
E3 CT
Charge Timer Set Input. A capacitor (C
CT
) from CT to GND sets the prequalification/dead-battery
and fast-charge fault timers. Use 0.1FF for 180-minute fast-charge time limit and 30-minute
prequalification/dead-battery time limit. Connect to GND to disable the timer.
E4 THM
Thermistor Input. Connect a negative temperature coefficient (NTC) thermistor from THM to GND.
Connect a resistor equal to the thermistor’s +25NC resistance from THM to AVL. Thermistor adjusts
the charge current and termination voltage as described in the JEITA specification for safe use of
secondary Li+ batteries. See Figure 10. To disable the THM operation, bias V
THM
midway between
AVL and GND.
E5 AVL
5V Linear Regulator to Power Low-Noise Internal Circuits. Bypass AVL to GND with a 0.1FF ceramic
capacitor. Powering external loads from AVL is not recommended.
E6 GND
Ground. GND is the low-noise ground connection for the internal circuitry. See the PCB Layout
section for more details.