Rainbow Electronics MAX8508 - Manual

General Description
The MAX8506/MAX8507/MAX8508 integrate a PWM step-
down DC-DC regulator and a 75mΩ (typ) bypass FET to
power the PA in WCDMA and cdmaOne™ cell phones.
The supply voltage range is from 2.6V to 5.5V, and the
guaranteed output current is 600mA. One megahertz
PWM switching allows for small external components.
The MAX8506 and MAX8507 are dynamically controlled
to provide varying output voltages from 0.4V to 3.4V. The
MAX8508 is externally programmed for fixed 0.75V to
3.4V output. Digital logic enables a high-power (HP)
bypass mode that connects the output directly to the bat-
tery for all versions. The MAX8506/MAX8507/MAX8508
are designed so the output settles in less than 30µs for a
full-scale change in output voltage and load current.
The MAX8506/MAX8507/MAX8508 are offered in 16-pin
4mm x 4mm thin QFN packages (0.8mm max height).
Applications
WCDMA/NCDMA Cell Phones
Wireless PDAs, Palmtops, and Notebook
Computers
Wireless Modems
Features
♦ Integrated 75mΩ (typ) Bypass FET
♦ 38mV Dropout at 600mA Load
♦ Up to 94% Efficiency
♦ Dynamically Adjustable Output from 0.4V to 3.4V
(MAX8506, MAX8507)
♦ Externally Fixed Output from 0.75V to 3.4V
(MAX8508)
♦ 1MHz Fixed-Frequency PWM Switching
♦ 600mA Guaranteed Output Current
♦ Shutdown Mode 0.1µA (typ)
♦ 16-Pin Thin QFN (4mm x 4mm, 0.8mm max Height)
MAX8506/MAX8507/MAX8508
PWM Step-Down DC-DC Converters with 75m Ω
Bypass FET for WCDMA and cdmaOne Handsets
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-2918; Rev 1; 1/04
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
PART TEMP RANGE PIN-PACKAGE
MAX8506 ETE -40°C to +85°C 16 Thin QFN
MAX8507 ETE -40°C to +85°C 16 Thin QFN
MAX8508 ETE -40°C to +85°C 16 Thin QFN
cdmaOne is a trademark of CDMA Development Group. Pin Configurations appear at end of data sheet.
Typical Application Circuits continued at end of data sheet.
CURRENT-
LIMIT
CONTROL
PWM
DAC
BATTP LX
OUT
COMP PGND GND
REFIN 1MHz
OSC
REF
HP
INPUT
2.6V TO 5.5V 4.7µH
OUTPUT
0.4V TO 3.4V OR V BATT
4.7µF
0.3Ω
0.4Ω
0.075Ω
BATT
REF
2.2µF
0.22µF
SKIP
SHDN
R C *
C C *
MAX8506
MAX8507
*
10
15
R C (kΩ)
1500
1000
C C (pF)
100
100
C f (pF)
MAX8506
MAX8507
C f *
Typical Application Circuits (MAX8506/MAX8507)