Microprocessor Supervisory
Circuit in 4-Lead SC70
ADM6384
Rev. 0
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However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
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Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 © 2005 Analog Devices, Inc. All rights reserved.
FEATURES
Precision power supply monitoring
31 reset threshold options
1.58 V to 5.0 V
Four reset timeouts
1 ms, 20 ms, 140 ms, 1120 ms
Manual reset input
Reset output stage
Push-pull active-low
Guaranteed reset output valid to VCC = 1 V
Power supply glitch immunity
Specified over −40°C to +125°C temperature range
4-lead SC70 package
APPLICATIONS
Microprocessor systems
Computers
Controllers
Intelligent instruments
Portable equipment
GENERAL DESCRIPTION
The ADM6384 is a supervisory circuit that monitors power
supply voltage levels in microprocessor-based systems. A
power-on reset signal is generated when the supply voltage
rises to a preset threshold level. The debounced manual reset
input of the ADM6384 can be used to initiate a reset by means
of an external push-button or logic signal.
The part is available in a choice of 31 reset threshold options,
from 1.58 V to 5.0 V. The minimum reset timeout periods are
1 ms, 20 ms, 140 ms, and 1120 ms.
The ADM6384 is available in a 4-lead SC70 package and typi-
cally consumes only 7 μA, making it suitable for use in low
power, portable applications.
FUNCTIONAL BLOCK DIAGRAMS
ADM6384
VCC
GND
RESET
RESET
GENERATOR
DEBOUNCE
MR
VREF
05305-001
Figure 1.
RESET RESETMR
GND GND
ADM6384
V
CC
V
CC
μP
100kΩ
05305-002
Figure 2.
ADM6384
Rev. 0 | Page 2 of 12
TABLE OF CONTENTS
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
ESD Caution.................................................................................. 5
Pin Configuration and Function Descriptions............................. 6
Typical Performance Characteristics ............................................. 7
Circuit Description........................................................................... 9
Reset Output ................................................................................. 9
Manual Reset Input .......................................................................9
Application Information................................................................ 10
Negative-Going VCC Transients ................................................ 10
Ensuring Reset Valid to VCC = 0 V........................................... 10
Outline Dimensions ....................................................................... 11
Ordering Guide .......................................................................... 11
REVISION HISTORY
7/05—Revision 0: Initial Version
ADM6384
Rev. 0 | Page 3 of 12
SPECIFICATIONS
VCC = full operating range; TA = −40°C to +125°C, unless otherwise noted.
Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
SUPPLY
VCC Operating Voltage Range 1 5.5 V
Supply Current 7 13 μA VCC = 5.5 V, no load
6 11 μA VCC = 3.6 V, no load
4 7 μA VCC = 2.5 V, no load1
3 6 μA VCC = 1.8 V, no load1
RESET THRESHOLD VOLTAGE
ADM6384x50x 4.88 5.00 5.12 V
ADM6384x49x 4.78 4.90 5.02 V
ADM6384x48x 4.68 4.80 4.92 V
ADM6384x47x 4.58 4.70 4.82 V
ADM6384x46x 4.51 4.63 4.74 V
ADM6384x45x 4.39 4.5 4.61 V
ADM6384x44x 4.27 4.38 4.48 V
ADM6384x43x 4.19 4.30 4.41 V
ADM6384x42x 4.1 4.2 4.31 V
ADM6384x41x 4.0 4.1 4.2 V
ADM6384x40x 3.9 4.0 4.1 V
ADM6384x39x 3.8 3.9 4.0 V
ADM6384x38x 3.71 3.8 3.9 V
ADM6384x37x 3.61 3.7 3.79 V
ADM6384x36x 3.51 3.6 3.69 V
ADM6384x35x 3.41 3.5 3.59 V
ADM6384x34x 3.32 3.4 3.49 V
ADM6384x33x 3.22 3.3 3.38 V
ADM6384x32x 3.12 3.2 3.28 V
ADM6384x31x 3.00 3.08 3.15 V
ADM6384x30x 2.93 3.0 3.08 V
ADM6384x29x 2.85 2.93 3.00 V
ADM6384x28x 2.73 2.8 2.87 V
ADM6384x27x 2.63 2.70 2.77 V
ADM6384x26x 2.56 2.63 2.69 V
ADM6384x25x 2.44 2.5 2.56 V
ADM6384x24x 2.34 2.4 2.46 V
ADM6384x23x 2.26 2.31 2.37 V
ADM6384x22x 2.13 2.19 2.24 V
ADM6384x17x 1.62 1.67 1.71 V
ADM6384x16x 1.54 1.58 1.61 V
RESET THRESHOLD TEMPERATURE COEFFICIENT 60 ppm/°C
VCC to RESET DELAY 35 μs VCC falling at 10 mV/μs from VTH +
100 mV to VTH − 100 mV
RESET THRESHOLD HYSTERESIS 2 x VTH mV
RESET TIMEOUT PERIOD
ADM6384xxD1 1 2 ms
ADM6384xxD2 20 40 ms
ADM6384xxD3 140 280 ms
ADM6384xxD4 1120 2240 ms
ADM6384
Rev. 0 | Page 4 of 12
Parameter Min Typ Max Unit Test Conditions/Comments
MANUAL RESET INPUT
MR Input Threshold
VIL 0.3 × VCC V VCC < 4 V
0.8 V VCC > 4 V
VIH 0.7 × VCC V VCC < 4 V
2.4 V VCC > 4 V
MR Input Pulse Width 1 μs
MR Glitch Rejection 100 ns
MR Pull-Up Resistance 32 63 100 kV
MR to Reset Delay 200 ns
RESET Output Voltage
VOL 0.3 V VCC > = 1.0 V, ISINK = 80 μA
0.3 V VCC > = 2.5 V, ISINK = 1.2 mA
0.4 V VCC > = 4.5 V, ISINK = 3.2 mA
VOH 0.8 × VCC V VCC > = 2.5 V, ISOURCE = 500 μA
0.8 × VCC V VCC > = 4.5 V, I SOURCE = 800 μA
1 TA = 25oC only.
ADM6384
Rev. 0 | Page 5 of 12
ABSOLUTE MAXIMUM RATINGS
T = 25°C, unless otherwise noted.
A
Table 2. Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Parameter Rating
V−0.3 V to +6 V
CC
RESET −0.3 V to +6 V
Output Current ( RESET 20 mA
)
Operating Temperature Range −40°C to +125°C
Storage Temperature Range −65°C to +150°C
θ
JA Thermal Impedance, SC70 331°C/W
Soldering Temperature
Sn/Pb 240°C, 30 sec
Pb-Free 260°C, 40 sec
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degrada-
tion or loss of functionality.
ADM6384
Rev. 0 | Page 6 of 12
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
GND
1
RESET
2
V
CC
4
MR
3
ADM6384
TOP VIEW
(Not to Scale)
05305-003
Figure 3. Pin Configuration
Table 3. Pin Function Descriptions
Pin No. Name Description
1 GND Ground.
2 RESET Active-Low Reset Output. Asserted whenever VCC is below the reset threshold, VTH.
Push-pull output stage.
3 MR Manual Reset Input. This is an active-low input which, when forced low for at least 1 μs,
generates a reset. It features a 52 kV internal pull-up.
4 V Power Supply Voltage Being Monitored.
CC
ADM6384
Rev. 0 | Page 7 of 12
TYPICAL PERFORMANCE CHARACTERISTICS
04535-006
TEMPERATURE (°C) 120–40 –20 0 20 40 60 80 100
I
CC
(μA)
10.0
9.5
7.5
7.0
6.5
9.0
8.5
8.0
6.0
5.5
5.0
4.5
4.0
3.5
04535-010
TEMPERATURE (°C) 120–40 0–20 4020 1008060
NORMALIZED RESET THRESHOLD
1.05
1.03
1.04
1.01
1.02
0.99
1.00
0.97
0.98
0.95
0.96
Figure 4. Supply Current vs. Temperature Figure 7. Normalized Reset Threshold vs. Temperature
04535-008
TEMPERATURE (°C) 120–40 0–20 4020 1008060
V
CC
TO RESET DELAY (μs)
100
90
80
60
70
40
50
20
10
30
0
04535-017
I
SINK
(mA) 70123456
V
OUT
(V)
0.20
0.15
0.10
0.05
0
to RESET Output Delay vs. Temperature
Figure 5. V Figure 8. Output Voltage Low vs. I
CC SINK
04535-007
TEMPERATURE (°C) 120–40 0–20 4020 1008060
NORMALIZED RESET TIMEOUT
1.20
1.15
1.10
1.05
0.95
1.00
0.90
0.85
0.80
04535-018
I
SOURCE
(mA) 1.00 0.2 0.4 0.6 0.8
V
OUT
(V)
2.92
2.90
2.88
2.86
2.84
2.82
Figure 6. Normalized Reset Timeout Period vs. Temperature Figure 9. Output Voltage High vs. ISOURCE
ADM6384
Rev. 0 | Page 8 of 12
05305-011
TEMPERATURE (°C)
–40 –20 0 20 40 60 80 100 120
MANUAL RESET TO RESET DELAY (ns)
340
280
320
300
260
220
240
200
180
160
140
120
100
05305-010
OVERDRIVE VOD (mV) 100010 100
MAXIMUM TRANSIENT DURATION (
μ
s)
160
120
140
100
60
80
40
20
0
V
TH
= 4.63V
V
TH
= 2.93V
RESET OCCURS ABOVE CURVE
Transient Duration vs. Reset Threshold Overdrive
Figure 10. Maximum V Figure 11. Manual Reset Minimum Pulse Width vs. Temperature
CC
ADM6384
Rev. 0 | Page 9 of 12
CIRCUIT DESCRIPTION
V
CC
1V
V
CC
0V
V
TH
V
TH
0V
V
CC
RESET
t
RD
t
RP
05305-012
The ADM6384 provides microprocessor supply voltage
supervision by controlling the microprocessor’s reset input.
Code execution errors are avoided during power-up, power-
down, and brownout conditions by asserting a reset signal
when the supply voltage is below a preset threshold. In addition,
the ADM6384 allows supply voltage stabilization with a fixed
timeout before the reset deasserts after the supply voltage
rises above the threshold. If the user detects a problem with
the system’s operation, a manual reset input is available to reset
the microprocessor by means of an external push-button,
for example.
Figure 12. Reset Timing Diagram
MANUAL RESET INPUT
The ADM6384 features a manual reset input (MR) which, when
driven low, asserts the reset output. When MR transitions from
low to high, reset remains asserted for the duration of the reset
active timeout period before deasserting. The
RESET OUTPUT MR input has a
52 kΩ internal pull-up so that the input is always high when
unconnected. An external push-button switch can be connected
between
The ADM6384 features an active-low push-pull reset output.
The reset signal is guaranteed to be logic low for VCC down
to 1 V. MR and ground so that the user can generate a reset.
Debounce circuitry for this purpose is integrated on-chip. Noise
immunity is provided on the
The reset output is asserted when VCC is below the reset
threshold (V MR input, and fast, negative-going
transients of up to 100 ns (typ) are ignored. A 0.1 μF capacitor
between
TH) or when MR is driven low. Reset remains
asserted for the duration of the reset active timeout period
(t MR and ground provides additional noise immunity.
RP) after VCC rises above the reset threshold or after MR
transitions from low to high. Figure 12 illustrates the behavior
of the reset outputs.
ADM6384
Rev. 0 | Page 10 of 12
APPLICATION INFORMATION
NEGATIVE-GOING VCC TRANSIENTS ENSURING RESET VALID TO VCC = 0 V
To avoid unnecessary resets caused by fast power supply
transients, the ADM6384 is equipped with glitch rejection
circuitry. The typical performance characteristic in
Both active-low and active-high reset outputs are guaranteed to
be valid for VCC as low as 1 V. However, by using an external
resistor with push-pull configured reset outputs, valid outputs
for V
Figure 10
plots VCC transient duration versus the transient magnitude.
The curves show combinations of transient magnitude and
duration for which a reset is not generated for 4.63 V and
2.93 V reset threshold parts. For example, with the 2.93 V
threshold, a transient that goes 100 mV below the threshold
and lasts 8 μs typically does not cause a reset, but if the transient
is any bigger in magnitude or duration, a reset is generated. An
optional 0.1 μF bypass capacitor mounted close to V
CC as low as 0 V are possible. For an active-low reset
output, a resistor connected between RESET and ground pulls
the output low when it is unable to sink current. A large
resistance such as 100 kΩ should be used so that it does not
overload the reset output when VCC is above 1 V.
RESET
GND
ADM6384
100kΩ
05305-013
V
CC
CC provides
additional glitch rejection.
= 0 V
Figure 13. Ensuring Reset Valid to VCC
ADM6384
Rev. 0 | Page 11 of 12
OUTLINE DIMENSIONS
*PACKAGE OUTLINE CORRESPONDS IN FULL TO EIAJ SC82
EXCEPT FOR WIDTH OF PIN-2 AS SHOWN
0.30
0.15
0.10 MAX
1.00
0.80
SEATING
PLANE 0.18
0.10
0.30
0.10
0.10 COPLANARITY
2
43
1
2.20
1.80
PIN 1
0.50 BSC
*0.70
0.50
1.35
1.15 2.40
1.80
1.10
0.80
0.65 BSC
0.40
0.10
12°
8°
Figure 14. 4-Lead Thin Shrink Small Outline Transistor Package [SC70]
(KS-4)
Dimensions shown in millimeters
ADM6384YKS
__
D
_-
RL7
ORDERING QUANTITY
RL7: 3,000 PIECE REEL
GENERIC NUMBER
PACKAGE CODE
KS: 4-LEAD SC70
Z: LEAD FREE RESET THRESHOLD NUMBER
(16 TO 50)
RESET TIMEOUT PERIOD
1: 1ms (MIN)
2: 20ms (MIN)
3: 140s (MIN)
4: 1120s (MIN)
TEMPERATURE RANGE
Y: –40°C TO +125°C
05305-014
xx x
Figure 15. Ordering Code Structure
ORDERING GUIDE
Package Type Branding
Standard Models Reset Threshold (V) Reset Timeout (ms) Temperature Range Quantity
1
ADM6384YKS29D1-RL7 2.93 1 3k SC70-4 N0J
−40°C to +125°C
ADM6384YKS23D3-RL7 2.31 140 3k SC70-4
1 If ordering nonstandard models, complete the ordering code shown in Figure 15 by inserting reset timeout and reset threshold suffixes. Contact Sales for availability
of nonstandard models.
−40°C to +125°C N0J
ADM6384YKS29D3-RL7 2.93 140 3k SC70-4 N0J
−40°C to +125°C
ADM6384
Rev. 0 | Page 12 of 12
NOTES
© 2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05305–0–7/05(0)
