MAX1534ETE+T Maxim Integrated Products, MAX1534ETE+T Datasheet - Page 8

• Manufacturer Part Number: MAX1534ETE+T
• Description: IC PWR SUPPLY CONTROLLER 16TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1534ETE+T

• Applications: Power Supply Controller
• Voltage - Input: 4.5 ~ 24 V
• Current - Supply: 15µA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX1534 regulator provides efficient light-load
power conversion for notebook computers or hand-held
devices that require keep-alive power or standby
power. The main step-down buck regulator uses a
unique peak current-limited control scheme, providing
high efficiency at light loads over a wide load range.
Operation up to 100% duty cycle allows the lowest pos-
sible dropout voltage, increasing the usable supply
voltage range. Under no load, the MAX1534 consumes
High-Efficiency, Triple-Output, Keep-Alive
Power Supply for Notebook Computers
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PIN
5, 8
6, 7
10
11
12
13
14
15
16
1
2
3
4
9
PRESET
LDOIN
NAME
SHDN
OUT2
OUT1
GND
POK
ILIM
FB1
FB2
FB3
LX
BP
IN
Detailed Description
Shutdown Control Input. Drive SHDN above 1V to start up, and below 0.9V to shut down. LX is high
impedance in shut down, and supply current reduces to 3.5µA. Connect SHDN to IN for automatic
startup. SHDN can be connected to IN through a resistive voltage-divider to implement a
programmable undervoltage lockout.
Open-Drain Power-OK (POK) Output. POK asserts low while any output voltage is below the reset
threshold. Connect a 100kΩ pullup resistor to OUT_. POK is driven low in shut down. If not used,
leave this pin unconnected.
Ground. Connect backside pad to GND.
Peak LX Current Control Input. Connect to IN for 1000mA peak LX current. Connect to GND for
500mA peak LX current.
Inductor Connection. Connect LX to external inductor and diode as shown in Figure 1. Both LX pins
must be connected together on the PC board.
Buck Regulator Input Supply Voltage. Input voltage range is 4.5V to 24V. Both IN pins must be
connected together on the PC board.
Regulated LDO2 Output Voltage. Sources up to 160mA guaranteed. Bypass with 2.2µF (<0.2Ω
typical ESR) ceramic capacitor to GND.
Input Supply for both LDOs. Supply voltage can range from 2.5V to 5.5V. Bypass with 2.2µF capacitor
to GND (see Capacitor Selection and LDO Stability).
Regulated LDO1 Output Voltage. Sources up to 160mA guaranteed. Bypass with 2.2µF (<0.2Ω
typical ESR) ceramic capacitor to GND.
LDO Reference Noise Bypass. Bypass with a low-leakage 0.01µF ceramic capacitor for reduced
noise at both outputs.
Feedback Input for LDO1. For a fixed 3.3V output, connect PRESET and FB1 to GND. For an
adjustable output, connect PRESET = IN and connect a resistive divider between OUT1 and GND.
Feedback Input for LDO2. For a fixed 1.8V output, connect PRESET and FB2 to GND. For an
adjustable output, connect PRESET = IN and connect a resistive divider between OUT2 and GND.
Preset Feedback Select Input. Connect to GND for the preset 5V buck output voltage, preset 3.3V
OUT1 output voltage, and preset 1.8V OUT2 output voltage. Connect PRESET to IN to select
adjustable feedback mode for all three regulators.
Buck Outp ut Feed b ack Inp ut. For a fi xed 5.0V outp ut, connect P RE SE T to G N D and FB3 to O U T3. For
an ad j ustab l e outp ut, connect P RE SE T to IN and connect a r esi sti ve d i vi d er b etw een O U T3 and GN D .
only 1mW, and in shutdown mode, it draws only 3.5µA.
The internal 24V switching MOSFET, internal current
sensing, and a high-switching frequency minimize PC
board space and component costs.
The MAX1534 includes two low-noise, low-dropout,
low-quiescent-current linear regulators. The linear regu-
lators are available with preset output voltages of 3.3V
and 1.8V. Each linear regulator can supply loads up to
160mA.
FUNCTION
Pin Description