PHILIPS NE56631-19 Active-low system reset Datasheet

INTEGRATED CIRCUITS
NE56631-XX
Active-LOW system reset
Product data
Supersedes data of 2002 Oct 07
2003 Feb 14
Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
GENERAL DESCRIPTION
The NE56631-XX is a family of Active-LOW, power-on resets that
offers precision threshold voltage detection within ±3% and super
low operating supply current of typically 1.5 µA.
Several detection threshold voltages are available at 1.9 V, 2.0 V,
2.7 V, 2.8 V, 2.9 V, 3.0 V, 3.1 V, 4.2 V, 4.3 V, 4.4 V, 4.5 V, and 4.6 V.
Other thresholds are offered upon request at 100 mV steps from
1.9 V to 4.6 V.
With its ultra low supply current and high precision voltage threshold
detection capability, the NE56631-XX is well suited for various
battery powered applications such as reset circuits for logic and
microprocessors, voltage check, and level detecting.
FEATURES
• High precision threshold detection voltage:
• Super low operating supply current:
APPLICATIONS
• Reset for microprocessor and logic circuits
• Voltage level detection circuit
• Battery voltage check circuit
• Detection circuit for battery backup
VS ±3%
ICCH=1.5 µA typ.; ICCL=1.0 µA typ.
• Hysteresis voltage: 50 mV typ.
• Internal Power-On-Reset Delay time: 20 µs typ.
• Detection threshold voltage: 1.9 V, 2.0 V, 2.7 V, 2.8 V, 2.9 V,
3.0 V, 3.1 V, 4.2 V, 4.3 V, 4.4 V, 4.5 V, and 4.6 V
• Other detection threshold voltages available upon request at
100 mV steps from 1.9 V to 4.6 V
• Large low reset output current: 30 mA typ.
• Reset assertion with VCC down to 0.65 V typ.
SIMPLIFIED SYSTEM DIAGRAM
VCC
VCC
NE56631-XX
RESET
VOUT
LOGIC SYSTEM
GND
SL01739
Figure 1. Simplified system diagram.
2003 Feb 14
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
ORDERING INFORMATION
PACKAGE
TYPE NUMBER
NE56631-XXD
NAME
DESCRIPTION
TEMPERATURE
RANGE
SOT23-5 / SOT25 (SO5)
plastic small outline package; 5 leads (see dimensional drawing)
–20 to +75 °C
NOTE:
The device has 12 voltage output options, indicated by the XX on
the ‘Type number’.
XX
VOLTAGE (Typical)
19
1.9 V
20
2.0 V
27
2.7 V
28
2.8 V
29
2.9 V
30
3.0 V
31
3.1 V
42
4.2 V
43
4.3 V
44
4.4 V
45
4.5 V
46
4.6 V
PIN CONFIGURATION
PIN DESCRIPTION
PIN
NC
1
SUB
2
GND
3
5
VCC
NE56631-XX
4
SYMBOL
DESCRIPTION
1
NC
No connection.
2
SUB
Substrate. Connect to ground (GND).
3
GND
Ground. Negative supply.
4
VOUT
Reset output (RESET).
Active-LOW, open collector.
5
VCC
Positive supply voltage
VOUT
SL01737
Figure 2. Pin configuration.
MAXIMUM RATINGS
MIN.
MAX.
UNIT
VCC
SYMBOL
Supply voltage
–0.3
+10
V
Tamb
Ambient operating temperature
–20
+75
°C
Tstg
Storage temperature
–40
+125
°C
PD
Power dissipation
–
150
mW
2003 Feb 14
PARAMETER
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
ELECTRICAL CHARACTERISTICS
Tamb = 25 °C, unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
RL = 470 Ω; VOL ≤ 0.4 V;
VCC = HIGH-to-LOW
0.97 VS
VS
1.03 VS
V
RL = 470 Ω;
VCC = LOW-to-HIGH-to-LOW
30
50
100
mV
RL = 470 Ω; Tamb = –20 °C to +75 °C
–
±0.01
–
%/°C
VCC = VS(min) – 0.05 V; RL = 470 Ω
–
0.2
0.4
V
VCC = 10 V; VO = VCC
–
–
±0.1
V
Supply current (LOW Reset)
VCC = VS(min) – 0.05 V; RL = ∞
–
1.0
2.0
µA
ICCH
Supply current (HIGH Reset)
VCC = VS(typ) / 0.85 V; RL = ∞
–
1.5
2.5
µA
tPLH
HIGH-to-LOW delay time
CL = 100 pF; RL = 4.7 kΩ
–
20
60
µs
tPHL
LOW–to-HIGH delay time
CL = 100 pF; RL = 4.7 kΩ
–
20
60
µs
VOPL
Minimum operating threshold voltage
RL = 4.7 kΩ; VOL ≤ 0.4 V
–
0.65
0.80
V
IOL1
Output current (LOW Reset) 1
VO = 0.4 V; RL = 0;
VCC = VS(min) – 0.05 V
–
30
–
mA
IOL2
Output current (LOW Reset) 2
VO = 0.4 V; RL = 0;
VCC = VS(min) – 0.15 V;
Tamb = –30 °C to +80 °C
–
23
–
mA
VS
Detection threshold voltage
∆VS
Hysteresis voltage
VS/∆T
Detection threshold voltage
temperature coefficient
VOL
LOW-level output voltage
ILO
Output leakage current
ICCL
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
TYPICAL PERFORMANCE CURVES
OUTPUT CURRENT (RESET LOW), I OL (mA)
4.60
RL = 470 Ω
VOL ≤ 0.4 V
VCC = HIGH-to-LOW
DETECTION VOLTAGE, VS (mV)
4.55
4.50
4.45
4.40
–25
0
25
50
34
VO = 0.4 V
RL = 0
VCC = VS(min) – 0.05 V
33
32
31
30
29
28
–25
75
AMBIENT TEMPERATURE, Tamb (°C)
0
25
50
SL01845
SL01841
Figure 3. Detection voltage versus ambient temperature.
Figure 4. Detection voltage versus ambient temperature.
80
SUPPLY CURRENT (RESET LOW), I CCL ( µ A)
1.8
HYSTERESIS VOLTAGE, ∆ VS (mV)
VCC = VS(min) – 0.05 V
RL = ∞
1.7
1.6
1.5
1.4
1.3
–25
0
25
50
RL = 470 Ω
VCC = LOW-to-HIGH-to-LOW
70
60
50
40
30
20
–25
75
AMBIENT TEMPERATURE, Tamb (°C)
0
25
50
SL01842
Figure 6. Hysteresis voltage versus ambient temperature.
0.9
190
RL = 4.7 kΩ
VOL ≤ 0.4 V
LOW-LEVEL OUTPUT VOLTAGE, VOL (V)
MINIMUM OPERATING THRESHOLD VOLTAGE,
VOPL (V)
Figure 5. Supply current (Reset LOW) versus
ambient temperature.
0.8
0.7
0.6
0.5
0
25
50
VCC = VS(min) – 0.05 V
RL = 470 Ω
170
150
130
110
–25
75
AMBIENT TEMPERATURE, Tamb (°C)
0
25
50
75
AMBIENT TEMPERATURE, Tamb (°C)
SL01844
SL01843
Figure 7. Minimum operating threshold voltage versus
ambient temperature.
2003 Feb 14
75
AMBIENT TEMPERATURE, Tamb (°C)
SL01840
0.4
–25
75
AMBIENT TEMPERATURE, Tamb (°C)
Figure 8. LOW-level output voltage versus
ambient temperature.
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
TECHNICAL DISCUSSION
The NE56631-XX is a Bipolar IC designed to provide power source
monitoring and a system reset function in the event the power sags
below an acceptable level for the system to operate reliably. The IC
is designed to generate a reset signal for a wide range of
microprocessor and other logic systems. The NE56631-XX can
operate at supply voltage up to 10 volts. The series includes several
devices with precision threshold reset voltage values of 1.9, 2.0, 2.7,
2.8, 2.9, 3.0, 3.1, 4.2, 4.3, 4.4, 4.5, 4.6 V. The reset threshold
incorporates a typical hysteresis of 50 mV to prevent erratic
reasserts from being generated. An internal fixed delay time circuit
provides a fixed power-on-reset delay of typically 20 µs with a
guaranteed maximum delay of 60 µs.
output of the comparator to go to a HIGH state. This causes the
common emitter amplifier, Q1 to turn on pulling down the
non-inverting terminal of the op amp, which causes its output to go
to a HIGH state. This high output level turns on the output common
emitter transistor, Q2. The collector output of Q2 is pulled LOW
through the external pull-up resistor, thereby asserting the
Active-LOW reset.
The bipolar common emitter transistor, Q1and the op amp
establishes threshold hysteresis by turning on when the threshold
comparator goes to a HIGH state (when VCC sags to or below the
threshold level). With the output of Q2 connected to the
non-inverting terminal of the op amp, the non-inverting terminal of
the op amp has a level near ground at about 0.4 V when the reset is
asserted (Active-LOW). For the op amp to reverse its output, the
comparator output and Q1 must overcome the additional pull-down
voltage present on the op amp inverting input. The differential
voltage required to do this establishes the hysteresis voltage of the
sensed threshold voltage. Typically it is 50 mV.
The output of the NE56631-XX utilizes an open collector topology,
which requires an external pull-up resistor to VCC. Though this may
be regarded as a disadvantage, it is advantageous in many
sensitive applications. Since the open collector output cannot source
reset current when both are operated from a common supply, the
NE56631-XX offers a safe interconnect to a wide variety of
microprocessors.
When VCC voltage sags, and it is below the detection Threshold
(VSL), the device will assert a Reset LOW output at or near ground
potential. As VCC voltage rises from (VCC < VSL) to VSH or higher,
the Reset is released and the output follows VCC. Conversely,
decreases in VCC from (VCC > VSL) to VSL will cause the output to
be pulled to ground.
The NE56631-XX operates at low supply currents, typically 1.5 µA,
while offering high precision of the threshold detection (±3%).
Figure 9 is a functional block diagram of the NE56631-XX. The
internal reference source voltage is typically 0.65 V over the
temperature range. The reference voltage is connected to the
non-inverting input of the threshold comparator while the inverting
input monitors the supply voltage through a voltage divider network
made up of R1 and R2. The output of the comparator drives the
series base resistor, R3 of a common emitter amplifier, Q1. The
collector of Q1 is connected through R4 to the inverting terminal of
the op amp. The op amp output is connected to the series base
resistor, R5 of the output common emitter transistor, Q2. The
collector output of Q2 is connected to the non-inverting terminal of
the op amp which drives it.
Hysteresis Voltage = Released Voltage – Detection Threshold
Voltage
∆VS = VSH – VSL
where:
VSH = VSL + ∆VS
VSL = VSH – ∆VS
When VCC drops below the minimum operating voltage, typically
0.65 V, the output is undefined and the output reset low assertion is
not guaranteed. At this level of VCC the output will try to rise to VCC.
When the supply voltage sags to the threshold detection voltage, the
resistor divider network supplies a voltage to the inverting terminal of
the threshold comparator which is less than VREF, causing the
5
VCC
4
VOUT
3
GND
R1
CO1
R4
VREF
R2
R3
OP1
R5
Q2
Q1
SL01738
Figure 9. Functional diagram.
2003 Feb 14
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
TIMING DIAGRAM
The Timing Diagram in Figure 10 depicts the operation of the device.
Letters A–J on the Time axis indicates specific events.
D-E: Between “D” and “E”, VCC starts rising.
E: At “E”, VCC rises to the VSH level. Once again, the device
releases the hold on the VOUT reset. The Reset output tracks VCC
as it rises above VSH.
A: At “A”, VCC begins to increase. Also the VOUT voltage initially
increases but abruptly decreases when VCC reaches the level
(approximately 0.65 V) that activates the internal bias circuitry and
RESET is asserted.
F-G: At “F”, VCC is above the upper threshold and begins to fall,
causing VOUT to follow it. As long as VCC remains above the VSH,
no reset signal will be triggered. Before VCC falls to the VSH, it
begins to rise, causing VOUT to follow it. At “G”, VCC returns to
normal.
B: At “B”, VCC reaches the threshold level of VSH. At this point the
device releases the hold on the VOUT reset. The Reset output VOUT
tracks VCC as it rises above VSH (assuming the reset pull-up resistor
RPU is connected to VCC). In a microprocessor-based system these
events release the reset from the microprocessor, allowing the
microprocessor to function normally.
H: At event “H”, VCC falls until the VSL undervoltage detection
threshold is reached. At this level, a RESET signal is generated and
VOUT goes LOW.
C-D: At “C”, VCC begins to fall, causing VOUT to follow. VCC
continues to fall until the VSL undervoltage detection threshold is
reached at “D”. This causes a reset signal to be generated (VOUT
RESET goes LOW).
J: At “J”, the VCC voltage has decreased until normal internal
circuit bias is unable to maintain a VOUT reset. As a result, VCC may
rise to less than 0.65 V. As VCC decreases further, the VOUT reset
also decreases to zero.
∆VS
VSH
VSL
VCC
0
VOUT
0
A
B
C
D
E
F
G
H
J
TIME
SL01740
Figure 10. Timing diagram.
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
APPLICATION INFORMATION
VCC
SUPPLY
VCC
RPU
NE56631-XX
VOUT
CPU
RESET
VSS
GND
SL01741
Figure 11. Conventional reset application for NE56631-XX.
VCC
SUPPLY
R
D
VCC
RPU
NE56631-XX
VOUT
CPU
RESET
VSS
GND
SL01742
Figure 12. Power On Reset circuit for NE56631-XX.
The Power ON Reset Circuit shown in Figure 12 is an example of
obtaining a stable reset condition upon power-up. If power supply
rises abruptly, the RESET may go “HIGH” momentarily when VCC is
below the minimum operating voltage (0.85 V). To overcome this
undesirable response, a resistor in placed between positive supply,
VCC and VCC pin and a capacitor from VCC pin to ground. The RC
circuit solution works reasonably well for power-up as long as the
2003 Feb 14
power supply voltage rises faster than the RC time constant. The
RC network provides the necessary reset delay to hold the
microprocessor in reset until its circuitry settles down and normal
operation begins. When the supply turns off, the diode provides a
path for the capacitor to discharge to more quickly assert logic LOW
reset.
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
PACKING METHOD
The NE56631-XX is packed in reels, as shown in Figure 13.
GUARD
BAND
TAPE
REEL
ASSEMBLY
TAPE DETAIL
COVER TAPE
CARRIER TAPE
BARCODE
LABEL
BOX
SL01305
Figure 13. Tape and reel packing method.
2003 Feb 14
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
SOT23-5: plastic small outline package; 5 leads; body width 1.5 mm
1.35
2003 Feb 14
1.2
1.0
0.025
0.55
0.41
0.22
0.08
3.00
2.70
1.70
1.50
0.55
0.35
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Philips Semiconductors
Product data
Active-LOW system reset
NE56631-XX
REVISION HISTORY
Rev
Date
Description
_2
20030214
Product data (9397 750 11131); ECN 853-2328 29155 of 06 November 2002.
Supersedes data of 2002 Oct 07 (9397 750 10266).
Modifications:
• Page 6, Technical discussion; third paragraph: from “... typically 1.5 mA, ...” to “... typically 1.5 µA, ...”
_1
20021007
Product data (9397 750 10266); ECN 853–2328 27919 of 25 March 2002.
Data sheet status
Level
Data sheet status [1]
Product
status [2] [3]
Definitions
I
Objective data
Development
This data sheet contains data from the objective specification for product development.
Philips Semiconductors reserves the right to change the specification in any manner without notice.
II
Preliminary data
Qualification
This data sheet contains data from the preliminary specification. Supplementary data will be published
at a later date. Philips Semiconductors reserves the right to change the specification without notice, in
order to improve the design and supply the best possible product.
III
Product data
Production
This data sheet contains data from the product specification. Philips Semiconductors reserves the
right to make changes at any time in order to improve the design, manufacturing and supply. Relevant
changes will be communicated via a Customer Product/Process Change Notification (CPCN).
[1] Please consult the most recently issued data sheet before initiating or completing a design.
[2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL
http://www.semiconductors.philips.com.
[3] For data sheets describing multiple type numbers, the highest-level product status determines the data sheet status.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see
the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one or more of the limiting
values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given
in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no
representation or warranty that such applications will be suitable for the specified use without further testing or modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be
expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree
to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes in the products—including circuits, standard cells, and/or software—described
or contained herein in order to improve design and/or performance. When the product is in full production (status ‘Production’), relevant changes will be communicated
via a Customer Product/Process Change Notification (CPCN). Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys
no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent,
copyright, or mask work right infringement, unless otherwise specified.
 Koninklijke Philips Electronics N.V. 2003
All rights reserved. Printed in U.S.A.
Contact information
For additional information please visit
http://www.semiconductors.philips.com.
Fax: +31 40 27 24825
Date of release: 02-03
For sales offices addresses send e-mail to:
[email protected].
2003 Feb 14
Document order number:
11
9397 750 11131