RICOH R5105N

Microprocessor Supervisory Circuit
R5105N SERIES
NO. EA-159-070908
OUTLINE
The R5105N Series are CMOS-based µ con supervisory circuit, or high accuracy and ultra low supply current
voltage detector with built-in delay circuit and watchdog timer. When the supply voltage is down across the
threshold, or the watchdog timer does not detect the system clock from the µ con, the reset output is generated.
The voltage detector circuit is used for the system reset, etc. The detector threshold is fixed internally, and the
tolerance is ±1.0%. The released delay time (Power-on Reset Delay) circuit is built-in, and output delay time is
adjustable with an external capacitor. When the supply voltage becomes the released voltage, the reset state will
be maintained during the delay time. The time out period of the watchdog timer can be also set with an external
capacitor. The output type of the reset is selectable, Nch open-drain, or CMOS. The package is small SOT-23-6.
FEATURES
• Built-in a watchdog timer's time out period accuracy
±30%
• Timeout period for watchdog and generating a reset signal can be set by an external capacitor
• Detector Threshold Voltage ····························· 0.1V stepwise setting in the range from 1.5V to 5.5V
• Supply current ·················································· Typ. 11µA
• Operating Voltage ············································ 0.9V to 6.0V
• High Accuracy Output Voltage of Detector Threshold ············································· ±1.0%
• Power-on Reset Delay Time accuracy············· ±20%
• Power-on reset delay time of the voltage detector can be set with an external capacitor.
• Small Package ················································· SOT-23-6
APPLICATION
• Supervisory circuit for equipment with using microprocessors.
1
R5105N
BLOCK DIAGRAMS
R5105Nxx1A
VDD
+
CD
-
-
+
GND
WATCHDOG
TIMER
TW
CLOCK
DETECTOR
SCK
RESETB
R5105Nxx1C
VDD
CD
+
-
+
GND
TW
RESETB
2
WATCHDOG
TIMER
CLOCK
DETECTOR
SCK
R5105N
SELECTION GUIDE
The selection can be made with designating the part number as shown below:
R5105Nxx1x-TR ←part Number
↑ ↑↑ ↑
a bcd
Code
Descriptions
Designation of Package Type;
N: SOT-23-6 (2.8mmx2.9mm)
Designation of Detector Threshold Voltage (-VDET)
0.1V stepwise setting is possible in the range from 1.5V to 5.5V
Designation of the output type of RESETB
A: Nch open-drain output
C: CMOS output
a
b
c
d
Designation of Taping Type
PIN CONFIGURATION
SCK
1
6
CD
5
GND
4
RESETB
R5105NxxxA
TW
2
VDD
R5105NxxxC
3
SOT 23-6
PIN DESCRIPTION
Pin No
Symbol
Pin Description
1
SCK
Clock Input Pin from Microprocessor
2
TW
External Capacitor Pin for setting Reset and Watchdog Timer
Timeout Period
3
VDD
Power supply Pin
4
RESETB
5
GND
6
CD
Output Pin for Reset signal of Watchdog timer and Voltage
Detector. (Output “L” at detecting Detector Threshold and
Watchdog Timer Reset.)
Ground Pin
External Capacitor Pin for Setting delay time of Voltage Detector
3
R5105N
ABSOLUTE MAXIMUM RATINGS
Topt=25°C, VSS=0V
Symbol
VIN
Item
Output Voltage
VRESETB
-0.3∼7.0
V
Voltage of CD Pin
-0.3∼VIN+0.3
V
Voltage of TW Pin
-0.3∼VIN+0.3
V
Voltage of RESETB Pin
-0.3∼7.0
V
-0.3∼7.0
V
20
mA
250
mW
VSCK
Input Voltage
Voltage of SCK Pin
IRESETB
Output Current
Current of RESETB Pin
PD
4
Unit
Supply Voltage
VCT
VTW
Rating
Power Dissipation
Topt
Operating Temperature Range
-40∼+105
°C
Tstg
Storage Temperature Range
-55∼+125
°C
R5105N
ELECTRICAL CHARACTERISTICS
R5105NxxxA/C
Unless otherwise specified, VIN=6.0V, CT=0.1uF, Rpull-up=100kΩ
Topt=25°C
The number written in bold font is applied to the temperature range from -40°C to 105°C
Symbol
Item
VIN
Conditions
Min.
VIN=(-VDET)+0.5V
Clock pulse input
Voltage Detector
VIN pin Threshold
Supply Current
-VDET
Detector Threshold
∆-VDET/
∆Topt
Detector Threshold
Temperature Coefficient
Detector Threshold
Hysteresis
Output Delay Time
Output Current (RESETB
Output pin)
Output Current (RESETB
Output pin)
VHYS
tpLH
IDOUTN
IDOUTP
Max.
Unit
6.0
V
0.9
Operating Voltage
Iss
Typ.
11
x0.990
x0.972
15
x1.010
x1.015
(-VDET) (-VDET) (-VDET)
x0.03
x0.07
x0.05
340
467
370
CD=0.1µF
Nch, VDD=1.2V, VDS=0.1V
Pch, VDD=6.0V, VDS=0.5V
(R5105NxxxC)
Watchdog Timer
V
ppm/
°C
±100
-40°C≤Topt≤105°C
µA
V
ms
0.38
0.80
mA
0.65
0.90
mA
TWD
Watchdog Timeout period
CTW =0.1uF
230
310
450
ms
TWR
Reset Hold Time of WDT
CTW =0.1uF
29
34
48
ms
6.0
V
VINx0.8
VSCKH
SCK Input "H"
VSCKL
SCK Input "L"
TSCKW
SCK Input Pulse Width
VINx0.2
0.0
VSCKL=VINx0.2,
VSCKH=VINx0.8
500
V
ns
Bold type values are guaranteed by design.
TYPICAL APPLICATIONS
Power supply
Power supply
R
VDD
RESET
RESETB
CD
C CD
GND
VDD
VDD
µ P
R5105NxxxA
Series
VDD
TW
Series
CD
CTW
µ P
R5105NxxxC
I/O
SCK
RESET
RESETB
C CD
GND
I/O
SCK
TW
CTW
5
R5105N
TEST CIRCUIT
R(R5105NxxxA)
A
VDD
RESETB
R5105NxxxA/C
Clock Input
SCK
Series
CD
CCD
GND
Supply Current Test Circuit
6
TW
CTW
R5105N
TIMING DIAGRAM (R5105NxxxA/R5105NxxxC)
(Nch open-drain, RESETB pin is pulled up to VDD.)
VDD
tpHL
tpHL
CD
VTCD
TWDI
TWD
VrefH
TW
VrefL
SCK
tpLH
tpLH
TWR
(1)
(2)
(3)
(4)
(1)
7
R5105N
OPERATION
When the power supply, VIN pin voltage becomes more than the released voltage (+VDET), after the released
delay time (or the power on reset time tpLH), the output of RESETB becomes “H” level.
When the SCK pulse is input, the watchdog timer is cleared, and TW pin mode changes from the discharge
mode to the charge mode. When the TW pin voltage becomes higher than VREFH, the mode will change
into the discharge mode, and next watchdog time count starts.
Unless the SCK pulse is input, WDT will not be cleared, and during the charging period of TW pin,
RESETB="L".
When the VIN pin becomes lower than the detector threshold voltage(-VDET), RESETB outputs "L".
∗ Watchdog Timeout period/Reset hold time
The watchdog timeout period and reset hold time can be set with an external capacitor to TW pin.
The next equations describe the relation between the watchdog timeout period and the external capacitor
value, or the reset hold time and the external capacitor value.
t
WD(s)
= 3.1*10 × C (F)
6
tWR(s)=TWD/9
The watchdog timer (WDT) timeout period is determined with the discharge time of the external capacitor.
During the watchdog timeout period, if the clock pulse from the system is detected, WDT is cleared and the
capacitor is charged. When the charge of the capacitor completes, another watchdog timeout period starts
again. During the watchdog timeout period, if the clock pulse from the system is not detected, during the
next reset hold time RESETB pin outputs "L".
After starting the watchdog timeout period, (just after from the discharge of the external capacitor) even if the clock pulse
is input during the time period "TWDI", the clock pulse is ignored.
TWDI[s]=TWD/10
Released Delay Time (Power-on Reset delay time)
The released delay time can be set with an external capacitor connected to the CD pin. The next equation describes the
relation between the capacitance value and the released delay time (tpLH).
tpLH(s)=3.7×106× C(F)
When the VDD voltage becomes equal or less than (-VDET), discharge of the capacitor connected to the CD pin starts.
Therefore, if the discharge is not enough and VDD voltage returns to (+VDET) or more, thereafter the delay time
will be shorter than tpLH which is expected.
Minimum Operating Voltage
We specified the minimum operating voltage as the minimum input voltage in which the condition of RESETB pin being
0.1V or lower than 0.1V. (Herein, pull-up resistance is set as 100kΩ in the case of the Nch open-drain output type.
RESETB Output
RESETB pin's output type is selectable either the Nch open-drain output or CMOS output. If the Nch
open-drain type output is selected, the RESETB pin is pulled up with an external resistor to an appropriate
voltage source.
Clock Pulse Input
Built-in watchdog timer is cleared with the SCK clock pulse within the watchdog timeout period.
8
R5105N
Power on Reset Operation against the input glitch
VDD
(tpLH1 < tpLH)
+V DET
-V DET
0V
Complete Discharge
CD
+VTCD
-V TCD
0V
Incomplete Discharge
RESETB
0V
tpLH
tpLH1
APPLICATION NOTES
If a resistor is connected to the VDD pin, the operation might be unstable with the supply current of IC itself.
VDD
VDD
R1
VDD
R1
R1
VIN
R2
R5105
VIN
VIN
R5105
R5105
RESETB
R2
CMOS
RESETB
Output
RESETB
Connection examples affected by the conduction current
9
R5105N
TYPICAL CHARACTERISTICS
1)
Supply Current vs. Input Voltage
105℃
25℃
-50℃
0
2)
R510xN301A/C, R510xG301A/A
CURRENT Iss [uA]
CURRENT Iss [uA]
R510xN151A/C, R510xG151A/C
20
18
16
14
12
10
8
6
4
2
0
1
2
3
4
SUPPLY VOLTAGE [V]
5
6
20
18
16
14
12
10
8
6
4
2
0
105℃
25℃
-50℃
0
6
2.740
1.520
DETECT VOLTAGE [V]
DETECT VOLTAGE [V]
5
R510xN271A/C, R510xG271A/C
1.530
1.510
1.500
1.490
1.480
1.470
-50
-25
0
25
50
75
TEMPERATURE [℃]
100
125
R510xN421A/C R510xG421A/C
4.280
DETECT VOLTAGE [V]
2
3
4
SUPPLY VOLTAGE [V]
Detector Threshold vs. Temperature
R510xN151A/C, R510xG151A/C
4.260
4.240
4.220
4.200
4.180
4.160
4.140
4.120
-50
10
1
-25
0
25
50
75
TEMPERATURE [℃]
100
125
2.730
2.720
2.710
2.700
2.690
2.680
2.670
2.660
-50
-25
0
25
50
75
TEMPERATURE [℃]
100
125
R5105N
3)
Detector Threshold Hysteresis vs. Temperature
R510xN271A/C R510xG271A/C
7.0
6.0
6.0
HYSTERESIS [%]
HYSTERESIS [%]
R510xN151A/C R510xG151A/C
7.0
5.0
4.0
3.0
-50
-25
0
25
50
75
TEMPERATURE [℃]
100
5.0
4.0
3.0
-50
125
-25
0
25
50
75
TEMPERATURE [℃]
100
125
R510xN421A/C R510xG421A/C
HYSTERESIS [%]
7.000
6.000
5.000
4.000
3.000
-50
4)
-25
0
25
50
75
TEMPERATURE [℃]
100
125
Nch Driver Output Current vs. VDS Topt=25°C
R510xN, R510xG
20
VDD=6.0V
OUTPUT CURRENT　[mA]
18
16
VDD=4.0V
VDD=5.0V
14
VDD=3.0V
12
VDD=2.0V
10
8
VDD=1.5V
6
4
VDD=1.0V
2
0
0.0
0.2
0.4
0.6
0.8
VDS [V]
1.0
1.2
1.4
11
R5105N
5)
Nch Driver Output Current vs. VDD
R510xN, R510xG
20
18
18
14
OUTPUT CURRENT [mA]
Vds=0.3V
16
OUTPUT CURRENT [mA]
R510xN, R510xG
20
Topt=-40℃
12
25℃
10
8
105℃
6
16
Vds=0.5V
25℃
Topt=-40℃
14
12
10
4
8
105℃
6
4
2
2
0
0
0
0
1
2
3
4
SUPPLY VOLTAGE VDD [V]
5
1
6
2
3
4
5
SUPPLY VOLTAGE VDD [V]
6
6) Pch Driver Output Current vs. VDD
R510xN, R510xG
2.0
1.8
VDS=0.3V
1.6
OUTPUT CURRENT [mA]
OUTPUT CURRENT [mA]
1.8
1.4
1.2
1.0
-40℃
0.8
0.6
25℃
0.4
105℃
0.2
0
1
1.4
1.2
-40℃
1.0
25℃
0.8
0.6
105℃
0.4
0.2
2
3
4
SUPPLY VOLTAGE [V]
5
6
R510xN, R510xG
2.0
1.8
OUTPUT CURRENT [mA]
VDS=0.5V
1.6
0.0
0.0
VDS=1.0V
-40℃
1.6
25℃
1.4
1.2
105℃
1.0
0.8
0.6
0.4
0.2
0.0
0
12
R510xN, R510xG
2.0
1
2
3
4
SUPPLY VOLTAGE [V]
5
6
0
1
2
3
4
SUPPLY VOLTAGE [V]
5
6
R5105N
Released Delay Time vs. Temperature
R510xN, R510xG
R510xN, R510xG
500
480
460
440
420
400
380
360
340
320
300
Topt=25℃
0
9)
8)
POWER ON RESET DELAY
tpLH[ms]
POWER ON RESET DELAY
tpLH [ms]
7) Released Delay Time vs. Input Voltage
1
2
3
4
5
SUPPLY VOLTAGE [V]
6
500
480
460
440
420
400
380
360
340
320
300
-50 -25
7
Detector Output Delay Time vs. Temperature
VDD=6V
0
25 50 75 100 125 150
TEMPERATURE [℃]
10) WDT Reset Timer vs. Temperature
R510xN, R510xG
R510xN, R510xG
100
50
90
RESET TIME [msec]
46
70
TIME [usec]
48
1us
80
(-VDET)+1
60
INPUT
(-VDET)-1
50
40
30
20
10
42
40
38
36
34
0
-50
32
-25
0
25
50
75
TEMPERATURE [℃]
100
125
11) WDT Timeout Period vs. Temperature
30
-50
-25
0
25
50
75
TEMPERATURE [℃]
100
125
12) WDT Reset Timer vs. Input Voltage
R510xN, R510xG
R510xN, R510xG
400
50
380
48
360
46
RESET TIME [msec]
Timeout
Period [msec]
44
340
320
300
280
260
44
42
40
38
36
240
34
220
32
200
30
-50
-25
0
25
50
75
TEMPERATURE [℃]
100
125
1
2
3
4
SUPPLY VOLTAGE [V]
5
6
13
R5105N
13) WDT Timeout Period vs. Input Voltage
R510xN, R510xG
400
Timeout Period [msec]
380
360
340
320
300
280
260
240
220
200
1
14
2
3
4
SUPPLY VOLTAGE [V]
5
6