Low Voltage Detector with built-in
Delay Circuit
R3130N×××A/C, R3131N×××A/C
APPLICATION MANUAL
NO. EA-073-0012
Low Voltage Detector with built-in
Delay Circuit
R3130N×××A/C, R3131N×××A/C
OUTLINE
R3130N/R3131N Series are low voltage detector ICs with built-in delay circuit, high Detector Threshold accuracy
and ultra low supply current by CMOS process, which can be operated at low voltage.
These ICs can be used as system reset generator, and each of these ICs consists of a voltage reference, a com-
parator, resistors for setting voltage detector threshold, an output driver transistor, and an output delay generator.
Detector threshold is fixed internally with high accuracy and requires no adjustment. When Supply Voltage crosses
a setting detector threshold voltage from a high value to a lower value, this IC generates reset signal.
R3130N Series output “L” at detection mode, while R3131N Series output “H”.
Further, each of R3130N/R3131N Series embeds an output delay generator, when Supply Voltage crosses a setting
detector threshold voltage from a low value to a higher value, during a setting delay time which is fixed in the IC, this
IC keeps the reset condition.
Output Delay Time can be selected. (TYP 240ms is standard.)
.
Two output types, Nch open drain type and CMOS type, are available.
Since the package for these ICs are SOT23-3 (Mini-mold) package, high density mounting of the ICs on board is
possible.
FEATURES
•
Pin to Pin compatible with MAX 809/810 (R3130N××××: MAX 809, R3131N××××: MAX 810)
•
Ultra-low supply Current ........................................................ TYP 1.25µA (R313×N27××: V
DD
=3.0V)
.
•
Operating Voltage Range ........................................................ 1.0V to 6.0V (Topt=25°C)
•
Detector Threshold .................................................................. Setting with a step of 0.1V in the range of 1.6V to 4.8V
is possible.
•
Embedded Power on Reset Delay Time Circuit .................... Delay Time can be designated.
Refer to Selection Guide.
•
High Accuracy Detector Threshold......................................... ±1.5%
•
High Accuracy Output Delay Time ......................................... ±10.0%
•
Low Temperature-Drift Coefficient of Detector Threshold... TYP ±100ppm/°C
.
•
Two Output Types .................................................................... Nch Open Drain and CMOS
•
Small Package ........................................................................... SOT-23-3
1
R3130N×××A/C, R3131N×××A/C
APPLICATIONS
•
CPU & Logic Circuit Reset
•
Battery Checker
•
Window Comparator
•
Wave Shaping Circuit
•
Battery Back-Up Circuit
•
Power Failure Detector
BLOCK DIAGRAMS
•
R3130N×××
×××A
×××
Nch Open Drain Output
V
DD
V
DD
•
R3130N×××
×××C
×××
CMOS Output
-
+
Vref
GND
Delay
Circuit
-
OUT
+
Vref
GND
Delay
Circuit
OUT
•
R3131N×××
×××A
×××
Nch Open Drain Output
V
DD
•
R3131N×××
×××C
×××
CMOS Output
V
DD
-
+
Vref
GND
Delay
Circuit
-
OUT
+
Vref
GND
Delay
Circuit
OUT
2
R3130N×××A/C, R3131N×××A/C
TIMING CHART
Supply
Voltage
(V
DD
)
Detector
Threshold
V
DET
Minimum Operating
Voltage
V
SS
Supply
Voltage
(V
DD
)
Detector
Threshold
V
DET
Minimum Operating
Voltage
V
SS
Output Voltage
V
SS
Tdelay
Output Voltage
V
SS
Tdelay
R3130N Operation Diagram
•
Output Delay Operation
Output Delay Time, or Tdelay is specified as follows:
1. In the case of Nch Open Drain Output:
R3131N Operation Diagram
The time interval from rising edge of V
DD
pulse (1.0V→(V
DET
)+0.1V) to the time at which the output reaches
2.5V under the condition that the output pin (OUT) is pulled up to 5V through a 470kΩ resistor.
2. In the case of CMOS Output
The time interval from rising edge of V
DD
pulse (1.0V→(V
DET
)+0.1V) to the time at which the output reaches
V
DD
/2.
V
DET
+1.0V
Input Voltage
(V
DD
)
V
DET
+1.0V
Input Voltage
(V
DD
)
1.0V
GND
1.0V
GND
5.0V
V
DET
+0.1V
Output Voltage
Output Voltage
2.5V
(V
DET
+0.1V)/2
GND
Trst
Tdelay
GND
Trst
Tdelay
Nch Open Drain Output
CMOS Output
3
R3130N×××A/C, R3131N×××A/C
SELECTION GUIDE
The detector threshold , the output type, and Output delay time of R3130N series can be designated at the user’s
request by specifying the part number as follows:
R3130N×××××-TR
R3131N×××××-TR
↑ ↑↑↑ ↑
a bcd e
Code
Setting Detector Threshold (V
DET
)
a
Stepwise setting with a step of 0.1V in the range of 1.6V to 4.8V is possible.
The following 6 kinds of voltage are also standard.
2.63V 2.93V 3.08V 4.00V 4.40V 4.65V
,
,
,
,
,
Selection of Output Delay Time
b
E: 240ms (Standard) A: 50ms B: 100ms D: 200ms H: 400ms
*A, B, D, H versions can be produced only for 6 kinds of standard voltage items.
Designation Output type
c
d
e
A: Nch Open Drain
C: CMOS
Description of last one digit of 6 kinds of standard voltage items.
Designation of Taping Direction
(Refer to Taping Specification)
Contents
←Part
Number
←Part
Number
PIN CONFIGURATION
SOT-23-3
3
MARK SIDE
1
2
4
