ADP2102 Analog Devices, ADP2102 Datasheet - Page 15

• Manufacturer Part Number: ADP2102
• Description: Low Duty Cycle, 600 mA, 3 MHz Synchronous Step-Down DC-to-DC Converter
• Manufacturer: Analog Devices

SOFT START
The ADP2102 has an internal soft start function that ramps the
output voltage in a controlled manner upon startup, therefore
limiting the inrush current. This prevents possible input voltage
drops when a battery or a high impedance power source is
connected to the input of the converter.
ENABLE
The device starts operation with soft start when the EN pin is
toggled from logic low to logic high. Pulling the EN pin low
forces the device into shutdown mode, with a typical shutdown
current of 0.01 μA. In shutdown mode, both the high-side and
low-side power switches are turned off, the internal resistor feed-
back divider is disconnected, and the entire control circuitry is
switched off. For proper operation, the device is in shutdown
mode when voltage applied to this pin is less than 0.4 V and
enabled when voltage applied is greater than 1.3 V. This pin
must not be left floating.
FB/OUT
AGND
EN
2
3
4
FIXED
ADJUSTABLE
REFERENCE
BANDGAP
R
R
UVLO
COMPENSATION
INTERNAL
AMPLIFIER
DETECT
RISE-
ERROR
SHUTDOWN
THERMAL
Figure 46. Internal Block Diagram
Rev. B | Page 15 of 24
MIN OFF-TIMER
REGULATION
COMPARATOR
REVERSE CURRENT
ON-TIME TIMER
UNDERVOLTAGE LOCKOUT
The undervoltage lockout circuit prevents the device from
operating incorrectly at low input voltages. It prevents the
converter from turning on the main switch and the synchronous
switch under undefined conditions and, therefore, prevents
deep discharge of the battery supply.
THERMAL SHUTDOWN
When the junction temperature, T
the device goes into thermal shutdown. In this mode, the high-
side and low-side power switches are off. The device resumes
operation when the junction temperature again falls below
135°C typical.
COMPARATOR
AVIN
8
CURRENT SENSE
AMPLIFIER
S
R
Q
OVERLAPPING
MODE
DRIVERS
1
NON-
J
PVIN
, exceeds 150°C typical,
7
6
5
LX
PGND
ADP2102