Datasheet

MAX6457–MAX6460
High-Voltage, Low-Current Voltage Monitors in
SOT Packages
13
Maxim Integrated
GND
IN+
15V
CC
OUT
MAX6457
SOT23
TOP VIEW
2
34
GND
IN-IN+
16V
CC
5 OUTB
OUTA
MAX6459
SOT23
2
34
GND
IN-IN+
15V
CC
OUT
MAX6458
SOT23
2
34
GND
IN-IN+
16V
CC
5 REF
OUT
MAX6460
SOT23
2
34
CLEAR
Pin Configurations
4) Calculate R1
Monitoring Voltages Other than V
CC
The MAX6457–MAX6460 can monitor voltages other than
V
CC
(Figure 12). Calculate V
TRIP
as shown in the
Programming the Trip Voltage (V
TRIP
) section. The moni-
tored voltage (V
MON
) is independent of V
CC
. V
IN
+ must
be within the specified operating range: 0 to V
CC
.
Interfacing to Voltages Other than V
CC
The open-drain outputs of the MAX6457–MAX6460
allow the output voltage to be selected independent of
V
CC
. For systems requiring an output voltage other than
V
CC
, connect the pullup resistor between OUT, OUTA, or
OUTB and any desired voltage up to 28V (see Figure 13).
Monitoring Negative Voltages
Figure 14 shows the typical application circuit for moni-
toring negative voltages (V
NEG
) using the MAX6460.
Select a value for R1 between 25kΩ and 1MΩ. Use the
following equation to select R2:
where V
REF
= 2.25V and V
NEG
< 0. V
IN
+ must always
be within the specified operating range: 0 to V
CC
.
RR
V
V
NEG
REF
21 =×
-
RR RR
Mkk
M
TOTAL
123
4 2 223 273 36 06
3 94067
. . .
.
=
=Ω Ω Ω
=Ω
- -
- -
R
VR
V
R
VM
V
k
k
TH TOTAL
TRIPLOW
23
1 167 4 2
18 9
223 273
36 06
=
×
=
Ω
Ω
=
-
-
-
(. )(. )
.
.
. Ω