MAX1667EAP+T Maxim Integrated Products, MAX1667EAP+T Datasheet - Page 19

• Manufacturer Part Number: MAX1667EAP+T
• Description: IC SMART BATT CHGR LEVEL2 20SSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1667EAP+T

• Function: Charge Management
• Battery Type: All Battery Types
• Voltage - Supply: 7.5 V ~ 28 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 8. SMBus a) Write-Word and b) Read-Word Protocols
The ChargerStatus() command uses Read-Word proto-
col (Figure 8b). The command code for ChargerStatus()
is 0x13 (0b00010011). The ChargerStatus() command
returns information about thermistor impedance and the
MAX1667’s internal state. The Read-Word protocol
returns D15–D0. Table 8 describes the meaning of the
individual bits. The latched bits, THERMISTOR_HOT
and ALARM_INHIBITED, are cleared whenever BAT-
TERY_PRESENT = 0 or ChargerMode() is written with
POR_RESET = 1.
An interrupt is triggered (INT goes low) whenever power
is applied to DCIN, the BATTERY_PRESENT bit changes,
or the POWER_FAIL bit changes. BATTERY_PRESENT
and POWER_FAIL have interrupt masks that can be set
a) Write-Word Format
b) Read-Word Format
S
S
Legend:
S = Start Condition or Repeated Start Condition
ACK = Acknowledge (logic low)
W = Write Bit (logic low)
0b0001001
ADDRESS
MSB LSB
0b0001001
Preset to
ADDRESS
MSB LSB
SLAVE
Preset to
7 bits
SLAVE
7 bits
MASTER TO SLAVE
SLAVE TO MASTER
______________________________________________________________________________________
1b
W
0
1b
W
0
ACK
Alert-Response Address
1b
ACK
1b
ChargerStatus() =
ChargerMode() = 0x12
ChargingCurrent() = 0x14
ChargerVoltage() = 0x15
AlarmWarning() = 0x16
COMMAND
MSB LSB
BYTE
Interrupts and the
8 bits
COMMAND
MSB LSB
0x13
BYTE
8 bits
ChargerStatus()
ACK
Level 2 Smart Battery Charger
1b
ACK
1b
S
P = Stop Condition
NACK = NOT Acknowledge (logic high)
R = Read Bit (logic high)
0b0001001
ADDRESS
MSB LSB
MSB LSB
Preset to
D7
SLAVE
DATA
BYTE
7 bits
8 bits
LOW
Chemistry-Independent,
D0
or cleared via the ChargerMode() command. INT stays
low until the interrupt is cleared. There are two methods
for clearing the interrupt: issuing a ChargerStatus() com-
mand, and using a modified Receive Byte protocol with a
0x19 (0b0011001) Alert-Response address. The
MAX1667 responds to the Alert-Response address with
its address (0x13) left justified as the most significant bits
of the returned byte.
In most portable equipment, the DC power to charge
batteries enters through a two-conductor cylindrical
power jack. It is easy for the end user to add an
adapter to switch the DC power’s polarity. Polarized
capacitor C6 would be destroyed if a negative voltage
were applied. Diode D4 in Figure 7 prevents this from
happening.
__________Applications Information
1b
ACK
R
1
1b
ACK
1b
D15
MSB LSB
Negative Input Voltage Protection
DATA
BYTE
HIGH
8 bits
D7
MSB LSB
DATA
BYTE
8 bits
LOW
D8
D0
ACK
1b
ACK
1b
P
D15
MSB LSB
DATA
BYTE
HIGH
8 bits
D8
NACK
1b
P
19