TS3809/3810 Series
Microprocessor Reset Circuit
1/7 Version: C07
SOT-23
General Description
The TS3809/3810 series are used for microprocessor (µP) supervisory circuits to monitor the power supplies in µP
and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and
adjustments when used with +5V, +3.3V, +3.0V, +2.5V powered circuits.
These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a
preset threshold, keeping it asserted for at least 200ms after VCC has risen above the reset threshold. Reset
thresholds suitable for operation with a variety of supply voltages are available. TS3809/3810 series have push pull
outputs. TS3809 series have an active low RESET output, while the TS3810 has an active high RESET output The
reset comparator is designed to ignore fast transients on VCC, and the outputs are guaranteed to be in the correct
logic state for VCC down to 1.0V. Low supply current makes TS3809/3810 series ideal for use in portable equipment.
Ordering Information
Note: x is the threshold voltage type, option as:
A
B
: 4.38V
C
: 4.00V
D
: 3.08V
E
F
: 2.63V
G
: 2.25V
Part No.
Package
Packing
TS3809CXx RF
SOT-23
3Kpcs / 7” Reel
TS3810CXx RF
SOT-23
3Kpcs / 7” Reel
Features
● High Accurate: ±2%
● Precision monitoring of +3V, +3.3V and +5V Power
supply voltage
● Fully specified over temperature
● Available in three output configurations
● Push-Pull RESET low output (TS3809)
● Push-Pull (RESET) high output (TS3810)
● 200mS typ. Power-on reset pulse width
● 25µS supply current
● Guaranteed reset valid to Vcc=+1V
● Power supply transient immunity
Applications
● Battery-operated systems and Controllers
● Intelligent instruments
● Critical uP and uC power monitoring
● Portable / Battery powered equipment
● Automotive
Typical Application Circuit
Absolute Maximum Rating
Parameter
Symbol
Maximum
Unit
Terminal Voltage (with respect to Gnd)
VCC
GND - 0.3 to GND +6.5
V
RESET & (RESET) push-pull
VRESET
GND - 0.3 to VCC +0.3
V
Input Current, VCC
ICC
20
mA
Output Current, RESET, (RESET)
IO
5
mA
Power Dissipation
PD
(TJ-TA)/θJA
mW
Operating Junction Temperature Range
TJ.OPR
-40 ~ +125
oC
Storage Temperature Range
TSTG
-65 ~ +150
oC
Lead Soldering Temperature (260oC)
TLEAD
10
S
Pin Definition:
TS3809
TS3810
1. GND
1. GND
2. RESET
2. (RESET)
3. VCC
3. VCC
TS3809/3810 Series
Microprocessor Reset Circuit
2/7 Version: C07
Thermal Performance
Parameter
Symbol
Maximum
Unit
Thermal Resistance from Junction to Case
θJC
110
ºC/W
Thermal Resistance from Junction to ambient
θJA
250
ºC/W
Note: θJA is measured the PCB copper area of approximately 1in2 (Multi-layer). Needs to connect to VSS pin.
Electrical Specification (Ta = 25oC, unless otherwise specified.)
Parameter
Conditions
Symbol
Min
Typ
Max
Unit
Input Supply Voltage
Ta=-40oC~+85oC
VCC
1.0
--
6
V
Supply Current
VCC=VTH +1V
ICC
--
25
35
uA
TS3809/3810CXA
4.54
4.63
4.71
TS3809/3810CXB
4.29
4.38
4.46
TS3809/3810CXC
3.92
4.00
4.08
TS3809/3810CXD
3.02
3.08
3.15
TS3809/3810CXE
2.87
2.93
3.00
TS3809/3810CXF
2.57
2.63
2.69
Reset Threshold
TS3809/3810CXG
VTH
2.20
2.25
2.30
V
Reset Threshold
Temperature Coefficient
TA=0~+85ºC
VTHT
--
50
--
ppm/ oC
Set-up Time
VCC = 0 ~ (VTH - 100mV)
TSET
1
--
--
µS
VCC to Reset Delay
VCC = VTH ~ (VTH - 100mV)
TRD
--
20
--
µS
Reset Active Timeout Period
TA=0~+85ºC
TDELAY
140
200
260
mS
1.8V<VCC<VTH(MAX), ISINK =1.2mA
RESET Output (TS809)
Voltage Low
1.2V<VCC<1.8V, ISINK =50µA
VOL
--
--
0.3
V
RESET Output (TS809)
Voltage High
VCC > VTH(MAX), ISOURCE =500µA
VOH
0.8
VCC
--
--
V
(RESET) Output (TS810)
Voltage Low
VCC > VTH(MAX), ISINK =1.2mA
VOL
--
--
0.3
V
1.8V<VCC<VTH(MAX), ISOURCE =500µA
(RESET) Output (TS810)
Voltage High
1.2V<VCC<1.8V, ISOURCE =150µA
VOH
0.8
VCC
--
--
V
Hysteresis at Vcc
Input Voltage
VHVS
--
40
--
mV
TS3809/3810 Series
Microprocessor Reset Circuit
3/7 Version: C07
Block Diagram
Marking Information
Part No.
Identification
Code
Part No.
Identification
Code
TS3809CXA
CA
TS3810CXA
CH
TS3809CXB
CB
TS3810CXB
CI
TS3809CXC
CC
TS3810CXC
CJ
TS3809CXD
CD
TS3810CXD
CK
TS3809CXE
CE
TS3810CXE
CL
TS3809CXF
CF
TS3810CXF
CM
TS3809CXG
CG
TS3810CXG
CN
TS3809/3810 Series
Microprocessor Reset Circuit
4/7 Version: C07
Application Information
Negative-Going VCC transients in addition to issuing a reset to the µP during power-up, power-down, and brownout
conditions, the TS3809/3810 are relatively immune to short-duration negative-going Vcc transients (glitches).
The TS3809/3810 do not generate a reset pulse. The graph was generated using a negative going pulse applied to
Vcc, starting 0.5V above the actual reset threshold and ending below it by the magnitude indicated (reset comparator
overdrive). The graph indicates the maximum pulse width a negative going Vcc transient can have without causing a
reset pulse. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum
allowable pulse width decreases. Typically, a Vcc transient that goes 100mV below the reset threshold and lasts
20µS or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the Vcc pin
provides additional transient immunity.
Function Description
A microprocessor’s (µP’s) reset input starts the µP In a know state. The TS3809/3810 assert reset to prevent code-
execution errors during power-up, power-down, or brownout conditions. They assert a reset signal whenever the Vcc
supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after Vcc has risen above
the reset threshold. The TS3809/3810 have a push-pull output stage.
Ensuring a Valid Reset Output Down to Vcc=0
RESET is guaranteed to be a logic low for VCC > 1.0V. Once VCC exceeds the reset threshold, an internal timer
keeps RESET low for the reset timeout period; after this interval, RESET goes high. If a brownout condition occurs
(VCC dips below the reset threshold), RESET goes low. Any time VCC goes below the reset threshold, the internal
timer resets to zero, and RESET goes low. The internal timer starts after VCC returns above the reset threshold, and
RESET remains low for the reset timeout period. When Vcc falls below 1V, the TS3809/3810 reset output no longer
sinks current - it becomes an open circuit. Therefore, high impedance CMOS logic input connected to reset can drift
to undetermined voltages. This present no problem in most applications since most µP and other circuitry is
inoperative with Vcc below 1V.However, in applications where reset must be valid down to 0V, adding a pull down
resistor to reset causes and stray leakage currents to flow to ground, holding reset low (Figure 2.) R1’s value is not
critical; 100K is large enough not to load reset and small enough to pull RESET to ground. For the TS3809/3810 if
reset is required to remain valid for Vcc<1V.
Benefits of Highly Accurate Reset Threshold
Most µP supervisor ICs has reset threshold voltages between 5% and 10% below the value of nominal supply
voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10%
below nominal. When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the
supply is between 5% and 10% low, and where the reset many or may not be asserted
Timming Diagram
TS3809/3810 Series
Microprocessor Reset Circuit
5/7 Version: C07
Electrical Characteristics Curve
Figure 1. Threshold Voltage vs. Temperature
Figure 2. TDELAY vs. Temperature
Figure 3. Supply Current vs. Temperature
Figure 4. Supply Current vs. Threshold Voltage
Figure 5. Power-Down TDELAY vs. Temperature
Figure 6. Output Voltage vs. Output Current
TS3809/3810 Series
Microprocessor Reset Circuit
6/7 Version: C07
SOT-23 Mechanical Drawing
SOT-23 DIMENSION
MILLIMETERS
INCHES
DIM
MIN
MAX
MIN
MAX.
A
0.95 BSC
0.037 BSC
A1
1.9 BSC
0.074 BSC
B
2.60
3.00
0.102
0.118
C
1.40
1.70
0.055
0.067
D
2.80
3.10
0.110
0.122
E
1.00
1.30
0.039
0.051
F
0.00
0.10
0.000
0.004
G
0.35
0.50
0.014
0.020
H
0.10
0.20
0.004
0.008
I
0.30
0.60
0.012
0.024
J
5º
10º
5º
10º
TS3809/3810 Series
Microprocessor Reset Circuit
7/7 Version: C07
Notice
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assumes no responsibility or liability for any errors or inaccuracies.
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and/or use of TSC products including liability or warranties relating to fitness for a particular purpose, merchantability,
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