MAX8621Y Datasheet, PDF (1/18 Pages) Maxim Integrated Products – Dual Step-Down DC-DC Power-Management ICs for Portable Devices

19-3539; Rev 1; 8/05
EVAALVUAAILTAIOBNLEKIT
Dual Step-Down DC-DC Power-Management ICs
for Portable Devices
General Description
The MAX8621Y/MAX8621Z power-management inte-
grated circuits (PMICs) are designed for a variety of
portable devices including cellular handsets. These
PMICs include two high-efficiency step-down DC-DC
converters, four low-dropout linear regulators (LDOs)
with pin-programmable capability, one open-drain dri-
ver, a 60ms (typ) reset timer, and power-on/off control
logic. These devices offer high efficiency with a no-load
supply current of 160µA, and their small thin QFN 4mm
x 4mm package makes them ideal for portable devices.
The step-down DC-DC converters utilize a proprietary
4MHz hysteretic-PWM control scheme that allows for
ultra-small external components. Internal synchronous
rectification improves efficiency and eliminates the
external Schottky diode that is required in conventional
step-down converters. The output voltage is adjustable
from 0.6V to 3.3V. The output current is guaranteed up
to 500mA.
The four LDOs offer low 45µV_RMS output noise and low
dropout of only 100mV at 100mA. OUT1 and OUT2
deliver 300mA (min) of continuous output current.
OUT3 and OUT4 deliver 150mA (min) of continuous
output current. The output voltages are pin selectable
by SEL1 and SEL2 for flexibility. The MAX8621Y/
MAX8621Z offer different sets of LDO output voltages.
A microprocessor reset output (RESET) monitors OUT1
and warns the system of impending power loss, allow-
ing safe shutdown. RESET asserts during power-up,
power-down, shutdown, and fault conditions where
V_OUT1 is below its regulation voltage.
A 200mA driver output is provided to control LED back-
lighting or provide an open-drain connection for resis-
tors such as in feedback networks.
Applications
Cellular Handsets
Smart Phones, PDAs
Digital Cameras
MP3 Players
Wireless LAN
Pin Configuration appears at end of data sheet.
Features
♦ Two 500mA Step-Down Converters
Up to 4MHz Switching Frequency
Adjustable Output from 0.6V to 3.3V
♦ Four Low-Noise LDOs with Pin-Programmable
Output Voltages
♦ One Open-Drain Driver
♦ 60ms (typ) Reset Timer
♦ Power-On/Off Control Logic and Sequencing
♦ 4mm x 4mm x 0.8mm 24-Pin Thin QFN
Ordering Information
PART
MAX8621YETG
TEMP RANGE
-40°C to +85°C
MAX8621YETG+ -40°C to +85°C
MAX8621ZETG -40°C to +85°C
MAX8621ZETG+ -40°C to +85°C
+ Denotes lead-free package.
PIN-PACKAGE
24 Thin QFN
4mm x 4mm (T2444-4)
24 Thin QFN
4mm x 4mm (T2444-4)
24 Thin QFN
4mm x 4mm (T2444-4)
24 Thin QFN
4mm x 4mm (T2444-4)
Typical Operating Circuit
INPUT
2.6V TO 5.5V
LX1
IN1
MAX8621Y FB1
MAX8621Z
IN2
BUCK1
1.375V, 500mA
IN3
PWRON
SEL1
SEL2
EN2
EN3
EN4
ENDR
REFBP
PGND1
LX2
FB2
PGND2
OUT1
RESET
OUT2
OUT3
OUT4
GND
DR
BUCK2
1.8V, 500mA
OUT1
2.6V, 300mA
RESET
OUT2
2.6V, 300mA
OUT3
1.8V, 150mA
OUT4
3V, 150mA
INPUT
________________________________________________________________ Maxim Integrated Products 1
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.