MAX8515 MAXIM [Maxim Integrated Products], MAX8515 Datasheet - Page 4

• Manufacturer Part Number: MAX8515
• Description: Wide-Input 0.6V Shunt Regulators for Isolated DC-to-DC Converters
• Manufacturer: MAXIM [Maxim Integrated Products]

The MAX8515A/MAX8515 adjustable shunt regulators
feature isolated supply inputs and outputs, ideal for isolat-
ed power-supply applications using an optocoupler in the
feedback path. The MAX8515A/MAX8515 sink 20mA with
V
device to operate from 1.7V to 28V. The MAX8515A/
MAX8515 compare the FB input to a precision 600mV
reference. If the FB input is low, OUT sinks no current. If
FB rises above 600mV, OUT sinks up to 20mA.
Figure 1 shows the MAX8515A/MAX8515 configured as a
shunt regulator. Connect FB to OUT for an output voltage
of 0.6V. Connect a 1.0µF capacitor from OUT to GND
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC Converters
(V
4
OUT
IN
_______________________________________________________________________________________
= 3.3V, I
PIN
1
2
3
4
5
at 0.2V. The wide input supply range allows the
OUT
-0.1
-0.2
-0.3
0.6
0.5
0.4
0.3
0.2
0.1
0
Applications Information
= 5mA, FB = OUT, circuit in Figure 1, C1 = 0.1µF, C2 = 1µF, T
NAME
PGND
0
GND
OUT
FB
IN
Shunt Regulator/Adjustable
OUTPUT VOLTAGE CHANGE
Detailed Description
5
vs. LOAD CURRENT
LOAD CURRENT (mA)
Power Ground. Connect PGND and GND together.
Analog Ground. Connect GND and PGND together.
Output. Connect a ceramic capacitor from OUT to GND. See the Applications Information section.
Supply Input. Connect a 0.1µF capacitor to GND.
Feedback Input. Regulates to 600mV.
10
Voltage Reference
15
Typical Operating Characteristics (continued)
20
when the output voltage is 0.6V. A resistor-divider con-
nected from OUT to GND produces higher output volt-
ages and allows for a smaller output capacitor. The
value of the output capacitor is inversely proportional to
the output voltage:
Set the current limit with a resistor connected from IN to
OUT. This type of shunt regulator is limited to low-current
applications. The MAX8515A/MAX8515 can typically sink
up to 20mA in this application.
Figure 2 shows the test circuits for gain and phase plots.
FUNCTION
A
= +25°C, unless otherwise specified.)
-0.01
0.05
0.04
0.03
0.02
0.01
0
3
C
V
OUT
OUT
OUTPUT VOLTAGE CHANGE
8
=
=
vs. INPUT VOLTAGE
0 6
1
µF
INPUT VOLTAGE (V)
.
13
×
×






1
Pin Description
V
+
0 6
18
OUT
.
R2
R1






23
28