Advanced Power
Electronics Corp.
FEATURES
Precision Monitoring of +2.5, +3V, +3.3V,
and +5V Power-Supply Voltages
Fully Specified Over Temperature
Available in Three Output Configurations
Push-Pull
RESET
Low Output(APE6809/APE6811)
Push-Pull RESET High Output(APE6810/APE6812)
200ms (Typ.)min Power-On Reset Pulse Width
25µA Supply Current
Guaranteed Reset Valid to VCC = +1.0V
Power Supply Transient Immunity
No External Components
Available in the 3-Pin Pb-Free SOT-23
and SC-70 Package
APE6809_6812
3PIN MICROPROCESSOR RESET CIRCUIT
DESCRIPTION
The APE6809_6812 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. The APE6809_6812 have push pull outputs. The
APE6809/APE6811 have an active low RESET output, while
the APE6810_6812 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
the APE6809_6812 ideal for use in portable equipment. The
APE6809_6812 is available in a 3-pin SOT-23 and SC-70
package.
TYPICAL APPLICATION
VCC
VCC
VCC
APE68XX
RESET
(RESET)
GND
Microprocessor
RESET
INPUT
GND
PACKAGE / ORDERING INFORMATION
APE68XX X - X
(Top View)
Voltage
A: 4.63
B: 4.38
C: 4.00
D: 3.08
E: 2.93
F: 2.63
G: 2.25
H: 2.70
I : 4.25
(Top View)
RESET
(RESET)
1
APE6811
APE6812
GND
2
SOT-23/SC-70
3 V
CC
Enable
09 : Active-Low
10 : Active-High
11 : Active-Low
12 : Active-High
Package
U : SC-70
N : SOT-23
GND
1
APE6809
APE6810
3 V
CC
RESET
(RESET)
2
SOT-23/SC-70
Data and specifications subject to change without notice
1
201102212
Advanced Power
Electronics Corp.
ABSOLUTE MAXIMUM RATINGS
(at T
A
=25°C)
VCC PIN Voltage (V
CC
) -----------------------------------
RESET, RESET(Push-Pull) PIN Voltage (V
RESET
) --
GND - 0.3V to GND + 6.5V
GND - 0.3V to VCC + 0.3V
APE6809_6812
Input Current, V
CC
(I
CC
) ------------------------------------ 20mA
Output Current, RESET, RESET (I
O
) ------------------ 5mA
Power Dissipation(P
D
) ------------------------------------- ( TJ-TA ) / Rthja
Storage Temperature Range(T
ST
) ---------------------- -60°C To 150°C
Operating Temperature Range(T
OP
) ------------------- -40°C To 85°C
Junction Temperature(T
J
) --------------------------------
Thermal Resistance from Junction to case(Rth
JC
)
Thermal Resistance from Junction to Ambient(Rth
JA
)
Note
-40°C To 150°C
o
110 C/W
o
250 C/W
Note. Rth
JA
is measured with the PCB copper area of approximately 1 in
2
(Multi-layer). that need connect to GND pin.
ELECTRICAL SPECIFICATIONS
(V
DD
=2.75V, T
A
=25℃, unless otherwise specified)
Parameter
Operating Vcc Range
Supply Current
SYM
V
Range
I
CC
TEST CONDITION
V
CC
= V
TH
+1.0V
APE6809_6812A
APE6809_6812B
APE6809_6812I
APE6809_6812C
Reset Threshold T
A
=25 C
o
MIN
1
-
4.54
4.29
4.16
3.92
3.02
2.87
2.64
2.57
2.2
-
1
-
160
-
0.8 V
CC
-
0.8 V
CC
-
TYP
-
25
4.63
4.38
4.25
4
3.08
2.93
2.7
2.63
2.25
50
-
20
200
-
-
-
-
40
MAX
6
35
4.71
4.46
4.33
4.08
3.15
3
2.75
2.69
2.3
-
-
-
260
0.3
-
0.3
-
-
UNITS
V
μA
V
TH
APE6809_6812D
APE6809_6812E
APE6809_6812H
APE6809_6812F
APE6809_6812G
V
Reset Threshold Tempco
Set-up Time
Vcc to Reset Delay
Reset Active Timeout Period
V
THT
T
S
T
RD
T
DELAY
V
OL
V
OH
V
OL
V
OH
V
Hys
T
A
= 0
o
C to +85
o
C
V
CC
= 0 to (V
TH
– 100mV)
Vcc=V
TH
to (V
TH
-100mV)
T
A
= 0
o
C to +85
o
C
1.8V<V
CC
< V
TH(min)
, I
SINK
= 1.2mA
1.2V < V
CC
< 1.8V, I
SINK
= 50uA
V
CC
> V
TH (max)
, I
SOURCE
= 500uA,
V
CC
> V
TH (max)
, I
SINK
= 1.2mA,
1.8V < V
CC
< V
TH (min)
, I
SOURCE
= 500uA
ppm/
o
C
μs
μs
ms
V
V
V
V
mV
RESET
Output Voltage
(APE6809/APE6811)
RESET
Output Voltage
(APE6810/APE6812)
Hysteresis at V
CC
1.2V < V
CC
< 1.8V, I
SOURCE
= 150uA
Input voltage
2
Advanced Power
Electronics Corp.
PIN DESCRIPTIONS
PIN SYMBOL
VCC
GND
RESET/(RESET)
PIN DESCRIPTION
Operating voltage input
Ground
Reset output pin
L: for APE6809/APE6811
H: for APE6810/APE6812
APE6809_6812
BLOCK DIAGRAM
VCC
P-MOS
-
+
Delay
Circuit
N-MOS
RESET
/ RESET
VREF
GND
FUNCTION DESCRIPTION
A microprocessor’s (µP’s) reset input starts the µP in a known state. The
APE6809_6812 asserts 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
200ms after VCC has risen above the reset threshold. The APE6809_6812 has a
push-pull output stage.
APPLICATION INFORMATION
Negative-Going VCC Transients
In addition to issuing a reset to the µP during power-up, power-down, and
brownout conditions, the APE6809_6812 is relatively immune to short-duration
negative-going VCC transients (glitches).
The APE6809_6812 does 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 50mV below the reset threshold A 0.1µF bypass
capacitor mounted as close as possible to the VCC pin provides additional transient
immunity.
3
Advanced Power
Electronics Corp.
APPLICATION INFORMATION
Ensuring a Valid Reset Output Down to VCC = 0
APE6809_6812
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 1.0V, the APE6809/APE6811 RESET output no longer sinks
current—it becomes an open circuit. Therefore, high-impedance CMOS logic inputs
connected to RESET can drift to undetermined voltages.
This presents no problem in most applications since most µP and other circuitry is
inoperative with VCC below 1.0V. However, in applications where RESET must be
valid down to 0V, adding a pull down resistor to causes any stray leakage currents to
flow to ground, holding RESET low. R1’s value is not critical; 100k is large enough not
to load RESET and small enough to pull RESET to ground. For the
APE6810/APE6812 if RESET is required to remain valid for VCC < 1.0V.
Ensuring a Valid Reset Output Down to VCC = 0
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 may or may not be
asserted.
4
Advanced Power
Electronics Corp.
TYPICAL PERFORMANCE CHARACTERISTICS
APE6809_6812
Temperature Vs Threshold Voltage
2.96
Threshold V oltage (V )
2.95
2.94
2.93
2.92
2.91
2.9
-50
-25
0
25
50
75
100
Temperature (℃)
V
TH
=2.93V
Temperature Vs Reset Active Timeout Period
250
240
230
220
210
200
190
180
170
160
150
-50
-25
0
25
50
75
100
Temperature (℃)
Reset A ctive Tim eout P eriod (m s)
Temperature Vs Supply Current
34
Reset A cS upply Current (uA )
32
30
28
26
24
22
20
-50
-25
0
25
50
75
100
Temperature (℃)
V
TH
=2.93V
Threshold Voltage Vs Supply Current
34
32
S upply Current (uA )
30
28
26
24
22
20
2.25
2.63
2.93
3.08
4
4.38
4.63
Threshold Voltage (V)
V
CC
=V
TH
+1V
Temperature Vs Power-Down Reset Delay
50
50
Temperature Vs Power-Down Reset Delay
Power-Down Reset Delay (uS)
45
40
35
30
25
20
15
10
5
0
-50
-25
0
25
50
75
100
V
OD
=100mV
V
OD
=200mV
V
OD
=50mV
V
TH
=2.93V
V
OD
=V
TH
-V
CC
Power-Down Reset Delay (uS)
45
40
35
30
25
20
15
10
5
0
-50
-25
0
25
50
V
OD
=200mV
V
OD
=50mV
V
TH
=2.25V
V
OD
=V
TH
-V
CC
V
OD
=100mV
75
100
Temperature (℃)
Temperature (℃)
5
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