MAX888ECJ Maxim, MAX888ECJ Datasheet - Page 12

• Manufacturer Part Number: MAX888ECJ
• Description: Wireless and Satellite Handset Power-Management ICs
• Manufacturer: Maxim

Wireless and Satellite Handset
Power-Management ICs
The MAX886/MAX888 contain one high-efficiency, step-
down DC-DC converter, four low-dropout linear regula-
tors, and one regulated charge pump. The output
voltages of the switching regulator and the linear regula-
tors are software-programmable through the serial inter-
face. The regulated charge-pump output is factory set
at 5.25V. The devices also include reset and start-up
timers and a low-battery detect comparator (Figure 3).
Figure 3. Functional Diagram
12
______________________________________________________________________________________
LBHYS
RESET
DGND
SYNC
SDA
SCL
OFF
REF
LBI
ON
OUT2
Detailed Description
DECODER
RESET AND
LOGIC
START UP
10k
TIMER
OSCILLATOR
DAC0
DAC1
DAC2
DAC3
DAC5
REF
ON0
ON4
5
REGULATOR
REGULATOR
SWITCHING
CHARGE
PUMP
REG4
ON1
ON2
ON5
ON2
Regulator 0 is a low-noise, step-down, synchronous
DC-DC converter that can source a minimum of
500mA. High operating frequency (up to 925kHz) mini-
mizes output voltage ripple and reduces the size and
cost of external components. Guaranteed 100% duty-
cycle operation provides the lowest possible dropout
voltage, extending the useful life of the battery supply.
LINEAR
LINEAR
LINEAR
LINEAR
REG1
REG2
REG3
REG5
500mA DC-DC Buck Regulator 0
C+
C-
LX
+
OUT1
OUT0
OUT4
GND
IN1
IN2
OUT2
IN3
OUT3
IN5
OUT5
CVH
CVL
IN0
BATT
PGND
IN4
ONSTAT
LBO