19-2528; Rev 1; 2/03
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC Converters
General Description
Features
The MAX8515A/MAX8515 shunt regulators simplify the
design of voltage regulation and overvoltage protection
(OVP) functions in high-accuracy isolated DC-to-DC con-
verters with output voltages as low as 0.6V. The devices
have supply voltage and feedback inputs separated from
the output shunt stage, and can operate directly from the
DC-to-DC converter output stage when the output voltage
is 1.8V to 18V. Alternately, the MAX8515A/MAX8515 input
stage can be biased from an unregulated 1.7V to 28V
supply, independent of DC-to-DC converter output volt-
age. The MAX8515A/MAX8515 shunts 20mA when the
output voltage is as low as 0.2V.
ꢀ MAX8515A
0.6V 0.5% Initial Accuracy at +25°C
0.6V 1% Accuracy from -40°C to +85°C
ꢀ MAX8515
0.6V 1% Initial Accuracy at +25°C
0.6V 1.8% Accuracy from -40°C to +85°C
ꢀ Sinks 20mA at 0.2V to 18V
ꢀ Input Voltage Range from 1.7V to 28V
ꢀ Directly Drives Optocouplers
ꢀ 0.2Ω Dynamic Output Impedance
ꢀ Space-Saving 5-Pin SC70 or SOT23 Packages
The MAX8515A features an initial output accuracy of
0.5% at +25°C and 1% from -40°C to +85°C and provides
the output voltage regulation function for isolated DC-to-
DC converters. The MAX8515 features initial output
accuracy of 1% at +25°C and 1.8% from -40°C to +85°C
and can provide an output OVP function for isolated DC-
to-DC converters. High open-loop bandwidth allows
design of high-bandwidth DC-to-DC converters.
Ordering Information
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
MAX8515AEXK-T
MAX8515AEZK-T
MAX8515EXK-T
MAX8515EZK-T
5 SC70-5
Low-cost, low-dropout linear regulators can be designed
with the MAX8515A/MAX8515 and an external NPN tran-
sistor for cost-conscious applications that do not require
overcurrent, short-circuit, or overtemperature protection.
5 Thin SOT23-5
5 SC70-5
5 Thin SOT23-5
The MAX8515/MAX8515A are available in space-saving
5-pin SC70 and SOT23 packages and are specified over
the -40°C to +85°C extended temperature range. An eval-
uation kit is available to speed designs.
Functional Diagram appears at end of data sheet.
Selector Guide appears at end of data sheet.
Applications
Isolated DC-to-DC Converters
Network, Telecom, and Cellular Base Station
Power Supplies
Typical Operating Circuit
Low-Dropout Linear Regulators
Shunt Regulator
INPUT SUPPLY
INPUT
1.7V TO 28V 1.7V TO 18V
Adjustable Voltage Reference
PRIMARY SIDE
PWM CONVERTER
CONTROL
Pin Configuration
VOLTAGE
TOP VIEW
IN
OUT
FB
PGND
GND
OUT
1
2
3
5
4
FB
IN
MAX8515A
MAX8515
MAX8515A
MAX8515
ISOLATED DC-DC
CONVERTER
OUTPUT
(DOWN TO 0.6V)
PGND
GND
x
SC7O/THIN SOT23
________________________________________________________________ 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.