ISL6131 데이터 시트보기 (PDF) - Renesas Electronics

부품명

상세내역

제조사

ISL6131

Multiple Voltage Supervisory ICs

Renesas Electronics 

ISL6131, ISL6132

Applications Usage

Using the ISL6131EVAL1Z and

ISL6132EVAL1Z Platforms

The ISL6131EVAL1Z platform is set up to monitor and report an

undervoltage condition on each of 12V, 5V, 3.3V and 1.2V

supplies to a -20% tolerance.

Each monitored supply has an individual STATUS output and an

AND’ed PGOOD output signal for all four supplies. An OFF LED is

the PGOOD indicator for all four supplies. The ENABLE input

enables or disables the voltage monitoring function. See Figures

10 to 17 for performance and function examples.

The ISL6132EVAL1Z platform is set up to monitor and report

either an undervoltage or an overvoltage condition on 5V and

12V supplies to a ±10% tolerance. There is an OV and a UV

STATUS output for each of the two supplies and individual

AND’ed PGOOD outputs when each voltage is within the

programmed voltage range. An OFF LED indicates compliance to

the voltage range upper and lower limits.

The ENABLE inputs enable or disable the voltage monitoring

functions for each monitor supply.

See Figures 18 to 24 for performance and function examples.

Figures 25 and 26 illustrate the ISL6131EVAL1Z and

ISL6132EVAL1Z platforms respectively in image and schematic.

Using the ISL6131, ISL6132 for Negative

Voltage Monitoring Applications

The ISL6131, ISL6132 can be used for -V monitoring because it

monitors any voltage that is more positive relative to its GND pin.

With correct bias differential, these parts can monitor any

voltage, regardless of polarity or amplitude.

Using the ISL6131 for “Lossless” Sequencing

Applications

The ISL6131 can be used in a “lossless” sequencing application

in which a monitored output voltage determines the start of the

next sequenced turn-on. As shown in Figure 7, VMON_A input

looks at the common VIN of several DC-DC converters and

enables DC-DC_A with STATUS _A, once both VIN and ENABLE are

satisfied. VMON_B monitors the output of DC-DC_A, and when

the acceptable output voltage is reached, DC-DC_B is enabled

with STATUS_B output. This sequencing pattern continues until

all DC-DC outputs are on, at which time PGOOD signal is

released. A delay of 160ms from VMON > VVMONVth to STATUS

high ensures stability at each step prior to subsequent turn-on.

Additional ISL6131s can be employed in parallel to sequence any

number of DC-DC convertors in this fashion.

VIN

VOUT

EN DC-DC_A

VIN

VOUT

EN DC-DC_B

VIN

VOUT

EN DC-DC_C

ABC

STATUS

PGOOD

VMON_A

VMON_D

VDD

ENABLE

ISL6131 VMON_C

VMON_B

GND

FIGURE 7. ISL6131 “LOSSLESS” SEQUENCING CONFIGURATION

Using the ISL6131 for System Voltage and

Over-Temperature Monitoring

As a multi-voltage monitoring IC, the ISL6131 can monitor

over-temperature as well as voltage for more complete coverage

of system stability. Using a Negative Temperature Coefficient

(NTC) passive device in place of one of the resistors in a VMON

divider provides over-temperature monitoring either locally or

remotely.

Evaluations of this application configuration have involved the

QT0805T-202J, QT0805Y-502J and QT0805Y-103J NTCs from

Quality Thermistor.

ISL6131 over-temperature monitoring is not as accurate as

specific temperature monitor ICs, but this implementation

provides a cost-efficient solution with 5% tolerances achievable.

See Figures 8 and 9 for over-temperature sensing configuration

and operation results. In this example, the desired maximum

temperature is 100°C. The QT0805Y-103J NTC was placed at the

end of 3 feet of twisted pair wire to emulate a remote sensing

application. According to the Quality Thermistor data sheet, this

NTC device has a +25°C value of 10K and a +100°C value of

0.923K. An accompanying standard value resistor of 3.83K was

chosen for the divider so that at 100°C, VMON ~0.633V with the

bias voltage at 3.3V.

The resulting falling VMON trip point with the configuration

shown is ~0.634V, with ~0.642V for rising, which equates to

~95°C for under-temperature and ~97°C for over-temperature,

respectively. Choosing the standard resistor value above and

below R1 allows for small adjustments in the temperature trip

point.

FN9119 Rev 6.00

February 11, 2014

Page 7 of 15

Share Link: