TS3809/3810 Series
Microprocessor Reset Circuit
SOT-23
Pin Definition:
TS3809
TS3810
1. GND
1. GND
2. RESET
2. (RESET)
3. VCC
3. VCC
General Description
The TS3809/3810 series are used for microprocessor (µP) supervisory circuits to monitor the power supplies in
µ
P
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 V
CC
supply voltage declines below a
preset threshold, keeping it asserted for at least 200ms after V
CC
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 V
CC
, and the outputs are guaranteed to be in the correct
logic state for V
CC
down to 1.0V. Low supply current makes TS3809/3810 series ideal for use in portable equipment.
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
Ordering Information
Part No.
TS3809CXx RF
Package
SOT-23
Packing
3Kpcs / 7” Reel
3Kpcs / 7” Reel
TS3810CXx RF
SOT-23
Note:
x
is the threshold voltage type, option as:
A
: 4.63V
B
: 4.38V
C
: 4.00V
D
: 3.08V
E
: 2.93V
F
: 2.63V
G
: 2.25V
Typical Application Circuit
Applications
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●
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Battery-operated systems and Controllers
Intelligent instruments
Critical uP and uC power monitoring
Portable / Battery powered equipment
Automotive
Absolute Maximum Rating
Parameter
Terminal Voltage (with respect to Gnd)
RESET & (RESET) push-pull
Input Current, V
CC
Output Current, RESET, (RESET)
Power Dissipation
Operating Junction Temperature Range
Storage Temperature Range
Lead Soldering Temperature (260 C)
o
Symbol
V
CC
V
RESET
I
CC
I
O
P
D
T
J.OPR
T
STG
T
LEAD
Maximum
GND - 0.3 to GND +6.5
GND - 0.3 to V
CC
+0.3
20
5
(T
J
-T
A
)/θ
JA
-40 ~ +125
-65 ~ +150
10
Unit
V
V
mA
mA
mW
o
C
o
C
S
1/7
Version: C07
TS3809/3810 Series
Microprocessor Reset Circuit
Thermal Performance
Parameter
Thermal Resistance from Junction to Case
Thermal Resistance from Junction to ambient
2
Symbol
θ
JC
θ
JA
Maximum
110
250
Unit
ºC/W
ºC/W
Note:
θ
JA
is measured the PCB copper area of approximately 1in (Multi-layer). Needs to connect to V
SS
pin.
Electrical Specification
(
Ta = 25
o
C, unless otherwise specified.)
Parameter
Input Supply Voltage
Supply Current
o
Conditions
Ta=-40 C~+85 C
V
CC
=V
TH
+1V
TS3809/3810CXA
TS3809/3810CXB
TS3809/3810CXC
TS3809/3810CXD
TS3809/3810CXE
TS3809/3810CXF
TS3809/3810CXG
o
Symbol
V
CC
I
CC
Min
1.0
--
4.54
4.29
3.92
3.02
2.87
2.57
2.20
Typ
--
25
4.63
4.38
4.00
3.08
2.93
2.63
2.25
50
--
20
200
--
--
--
--
40
Max
6
35
4.71
4.46
4.08
3.15
3.00
2.69
2.30
--
--
--
260
0.3
--
0.3
--
--
Unit
V
uA
Reset Threshold
V
TH
V
Reset Threshold
Temperature Coefficient
Set-up Time
VCC to Reset Delay
Reset Active Timeout Period
RESET Output (TS809)
Voltage Low
RESET Output (TS809)
Voltage High
(RESET) Output (TS810)
Voltage Low
(RESET) Output (TS810)
Voltage High
Hysteresis at Vcc
T
A
=0~+85ºC
V
CC
= 0 ~ (V
TH
- 100mV)
V
CC
= V
TH
~ (V
TH
- 100mV)
T
A
=0~+85ºC
1.8V<V
CC
<V
TH(MAX)
, I
SINK
=1.2mA
1.2V<V
CC
<1.8V, I
SINK
=50µA
V
CC
> V
TH(MAX)
, I
SOURCE
=500µA
V
CC
> V
TH(MAX)
, I
SINK
=1.2mA
1.8V<V
CC
<V
TH(MAX)
, I
SOURCE
=500µA
1.2V<V
CC
<1.8V, I
SOURCE
=150µA
Input Voltage
V
THT
T
SET
T
RD
T
DELAY
V
OL
V
OH
V
OL
V
OH
V
HVS
--
1
--
140
--
0.8
VCC
--
0.8
VCC
--
ppm/ C
µS
µS
mS
V
V
V
V
mV
o
2/7
Version: C07
TS3809/3810 Series
Microprocessor Reset Circuit
Block Diagram
Marking Information
Part No.
TS3809CXA
TS3809CXB
TS3809CXC
TS3809CXD
TS3809CXE
TS3809CXF
TS3809CXG
Identification
Code
CA
CB
CC
CD
CE
CF
CG
Part No.
TS3810CXA
TS3810CXB
TS3810CXC
TS3810CXD
TS3810CXE
TS3810CXF
TS3810CXG
Identification
Code
CH
CI
CJ
CK
CL
CM
CN
3/7
Version: C07
TS3809/3810 Series
Microprocessor Reset Circuit
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
4/7
Version: C07
TS3809/3810 Series
Microprocessor Reset Circuit
Electrical Characteristics Curve
Figure 1. Threshold Voltage vs. Temperature
Figure 2. T
DELAY
vs. Temperature
Figure 3. Supply Current vs. Temperature
Figure 4. Supply Current vs. Threshold Voltage
Figure 5. Power-Down T
DELAY
vs. Temperature
Figure 6. Output Voltage vs. Output Current
5/7
Version: C07
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