Datasheet ADP1864 (Analog Devices)

Constant Frequency Current-Mode Step-Down DC-to-DC Control er in TSOT Data Sheet ADP1864 FEATURES GENERAL DESCRIPTION Wide input voltage range: 3.15 V to 14 V
The ADP1864 is a compact, inexpensive, constant-frequency,
Wide output voltage range: 0.8 V to input voltage
current-mode, step-down dc-to-dc control er. The ADP1864
Pin-to-pin compatible with LTC1772, LTC3801
drives a P-channel MOSFET that regulates an output voltage as
Up to 94% efficiency
low as 0.8 V with ±1.25% accuracy, for up to 5 A load currents,
0.8 V ± 1.25% reference accuracy over temperature
from input voltages as high as 14 V.
Internal soft start
The ADP1864 provides system flexibility by allowing accurate
100% duty cycle for low dropout voltage
setting of the current limit with an external resistor, and the
Current-mode operation for good line and load
output voltage is easily adjustable using two external resistors.
transient response
The ADP1864 includes an internal soft start to al ow quick
7 μA shutdown supply current
power-up while preventing input inrush current. Additional
235 μA quiescent supply current
safety features include short-circuit protection, output overvoltage
Short-circuit and overvoltage protection
protection, and input undervoltage protection. Current-mode
Small 6-lead TSOT package
control provides fast and stable load transient performance,
Supported by ADIsimPower™ design tool
while the 580 kHz operating frequency allows a small inductor

to be used in the system. To further the life of a battery source,
APPLICATIONS
the control er turns on the external P-channel MOSFET 100%
Wireless devices
of the duty cycle during dropout.
1- to 3-cell Li-Ion battery-powered applications
The ADP1864 operates over the −40°C to +125°C temperature
Set-top boxes
range and is available in a small, low profile, 6-lead TSOT package.
Processor core power supplies Hard disk drives TYPICAL APPLICATIONS DIAGRAM 25kΩ 1 COMP PGATE 6 VIN = 3.15V TO 14V 470pF 68pF ADP1864 0.03Ω 10µF 2 GND IN 5 80.6kΩ 5µH 2.5V, 2.0A 3 FB CS 4 174kΩ 47µF
001 05562- Figure 1.
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Document Outline Features Applications General Description Typical Applications Diagram Revision History Specifications Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Theory of Operation Loop Startup Short-Circuit Protection Undervoltage Lockout (UVLO) Overvoltage Lockout Protection (OVP) Soft Start Applications Information ADIsimPower Design Tool Duty Cycle Ripple Current Sense Resistor Inductor Value MOSFET Diode Input Capacitor Output Capacitor Feedback Resistors Layout Considerations Example Applications Circuits Outline Dimensions Ordering Guide