Holtek Semiconductor Inc HT7024A, HT7027A, HT7033A, HT7039A, HT7044A Datasheet

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Features

Low power consumption
·
Low temperature coefficient
·
Built-in high-stability reference source
·

Applications

Battery checkers
·
Level selectors
·
Power failure detectors
·

General Description

The HT70XX series is a set of three-terminal low power voltage detectors implemented in CMOS technology. Each voltage detector in the series detects a particular fixed voltage ranging from 2.4V to 7V. The voltage detectors consist of a high-precision and low power consumption standard voltage source, a comparator, hyster
HT70XX
Voltage Detector
Built-in hysteresis characteristic
·
TO-92 & SOT-89 package
·
Microcomputer reset
·
Battery memory backup
·
Non-volatile RAM signal storage protectors
·
esis circuit, and an output driver. CMOS tech nology ensures low power consumption.
Although designed primarily as fixed voltage detectors, these devices can be used with exter nal components to detect user specified thresh old voltages (NMOS open drain type only).
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Selection Table

Part No. Detectable Voltage Hysteresis Width Tolerance
HT7024A
HT7027A
HT7033A
HT7039A
HT7044A
HT7050A
HT7070A
Note: The output type selection codes are:
NMOS open drain normal open, active low
PMOS open drain normal open, active high
For example: The HT7070A is a 7V, NMOS open drain active low output
2.4V 0.12V
2.7V 0.135V
3.3V 0.165V
3.9V 0.195V
4.4V 0.22V
7V 0.35V
1 May 3, 2000
±5%
±5%
±5%
±5%
±5%
±5%
±5%
Output type selection table
V
Type V
DD
OUT
VDD>V
DET
A Hi-Z VSS

Block Diagram

N channel open drain output (normal open; active low)
(+) VDD£V
DET
(-)
HT70XX
A type
VDD
GND
VOUT
V
REF
V
OUT
V
DET
V
HYS
V
IN
2 May 3, 2000

Pin Assignment Pad Assignment

HT70XX
TO -92
HT70XX
OUTVDD VSS
Front V iew
B o tto m V ie w
SO T-89
OUT VDD VSS

Pad Coordinates

Pad No. X Y
1
2
-483.30 -379.50
-234.60 -399.50
3 443.90

Absolute Maximum Ratings

Unit: mm
-386.00
(0 ,0 )
1
2
VOUT
VIN
Chip size: 1317 ´ 1158 (mm)
3
GND
2
* The IC substrate should be connected to VDD in
the PCB layout artwork.
Supply Voltage...............................-0.3V to 26V Output Current.........................................50mA
Output Voltage ..............V
Power Consumption...............................200mW
-0.3V to VDD+0.3V
SS
Storage Temperature.................-50°Cto125°C
Operating Temperature ..................0°Cto70°C
Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maxi-
mum Ratings² may cause substantial damage to the device. Functional operation of this de­vice at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.
3 May 3, 2000

Electrical Characteristics

HT70XX
HT7024A
Symbol Parameter
V
V
I
V
I
DDV
DET
HYS
DD
DD
OL
DET
Hi®Lo Detectable Voltage ¾¾
Lo®Hi Detectable Voltage ¾¾
Hysteresis Width
Operating Current 8 No load
Operating Voltage
Output Sink Current 2
Temperature Coefficient
T
A
HT7027A
Symbol Parameter
V
V
I
V
I
DDV
DET
HYS
DD
DD
OL
DET
Hi®Lo Detectable Voltage ¾¾
Lo®Hi Detectable Voltage ¾¾
Hysteresis Width
Operating Current 8 No load
Operating Voltage
Output Sink Current 2
Temperature Coefficient
T
A
Ta=25°C
Test Conditions
Min. Typ. Max. Unit
V
DD
Conditions
2.28 2.4 2.52 V
2.325 2.52 2.772 V
¾¾
¾¾
V
=0.2V
OUT
0.02
V
DET
¾
1.5
0.5 1
0.05
V
DET
47
¾
0.1
V
DET
24 V
¾
mA
mA
¾ 0°C<Ta<70°C ¾±0.9 ¾ mV/°C
Ta=25°C
Test Conditions
Min. Typ. Max. Unit
V
DD
Conditions
2.565 2.7 2.835 V
2.616 2.835 3.118 V
¾¾
¾¾
V
=0.2V
OUT
0.02
V
DET
¾
1.5
0.5 1
0.05
V
DET
47
¾
0.1
V
DET
24 V
¾
mA
mA
¾ 0°C<Ta<70°C ¾±0.9 ¾ mV/°C
V
V
4 May 3, 2000
HT70XX
HT7033A
Symbol Parameter
V
V
I
V
I
DDV
DET
HYS
DD
DD
OL
DET
Hi®Lo Detectable Voltage ¾¾
Lo®Hi Detectable Voltage ¾¾
Hysteresis Width
Operating Current 8 No load
Operating Voltage
Output Sink Current 2.5
Temperature Coefficient
T
A
HT7039A
Symbol Parameter
V
V
I
V
I
DDV
DET
HYS
DD
DD
OL
DET
Hi®Lo Detectable Voltage ¾¾
Lo®Hi Detectable Voltage ¾¾
Hysteresis Width
Operating Current 8 No load
Operating Voltage
Output Sink Current 2.5
Temperature Coefficient
T
A
Ta=25°C
Test Conditions
V
DD
Conditions
Min. Typ. Max. Unit
3.135 3.3 3.465 V
3.197 3.465 3.811 V
¾¾
¾¾
V
=0.25V
OUT
0.02
V
DET
V
¾
1.5
1.2 2.5
0.05
DET
47
¾
0.1
V
DET
24 V
¾
mA
mA
¾ 0°C<Ta<70°C ¾±0.9 ¾ mV/°C
Ta=25°C
Test Conditions
Min. Typ. Max. Unit
DD
Conditions
V
3.705 3.9 4.095 V
3.779 4.095 4.504 V
¾¾
¾¾
V
=0.25V
OUT
0.02
V
DET
V
¾
1.5
1.2 2.5
0.05
DET
47
¾
0.1
V
DET
24 V
¾
mA
mA
¾ 0°C<Ta<70°C ¾±0.9 ¾ mV/°C
V
V
5 May 3, 2000
HT70XX
HT7044A
Symbol Parameter
V
V
I
V
I
DDV
DET
HYS
DD
DD
OL
DET
Hi®Lo Detectable Voltage ¾¾
Lo®Hi Detectable Voltage ¾¾
Hysteresis Width
Operating Current 8 No load
Operating Voltage
Output Sink Current 3.6
Temperature Coefficient
T
A
HT7050A
Symbol Parameter
V
V
I
V
I
DDV
DET
HYS
DD
DD
OL
DET
Hi®Lo Detectable Voltage ¾¾
Lo®Hi Detectable Voltage ¾¾
Hysteresis Width
Operating Current 8 No load
Operating Voltage
Output Sink Current 3.6
Temperature Coefficient
T
A
Ta=25°C
Test Conditions
Min. Typ. Max. Unit
V
DD
Conditions
4.18 4.4 4.62 V
4.263 4.62 5.082 V
¾¾
¾¾
V
=0.36V
OUT
0.02
V
¾
1.5
DET
0.05
V
DET
47
¾
36
0.1
V
DET
24 V
¾
V
mA
mA
¾ 0°C<Ta<70°C ¾±0.9 ¾ mV/°C
Ta=25°C
Test Conditions
Min. Typ. Max. Unit
V
DD
Conditions
4.75 5 5.25 V
4.845 5.25 5.775 V
¾¾
¾¾
V
=0.36V
OUT
0.02
V
DET
¾
2.1
0.05
V
DET
47
¾
36
0.1
V
DET
24 V
¾
mA
mA
¾ 0°C<Ta<70°C ¾±0.9 ¾ mV/°C
V
6 May 3, 2000
HT70XX
HT7070A
Symbol Parameter
V
V
I
V
I
DDV
DET
HYS
DD
DD
OL
DET
Hi®Lo Detectable Voltage ¾¾
Lo®Hi Detectable Voltage ¾¾
Hysteresis Width
Operating Current 8 No load
Operating Voltage
Output Sink Current 5
Temperature Coefficient
T
A
Test Conditions
V
DD
¾¾
¾¾
¾ 0°C<Ta<70°C ¾±0.9 ¾ mV/°C

Functional Description

The HT70XX series is a set of voltage detectors equipped with a high stability voltage reference which is connected to the negative input of a comparator¾ denoted as V figure for NMOS output voltage detector.
When the voltage drop to the positive input of the comparator (i,e,V
) is higher than V
B
VOUT goes high, M1 turns off, and V pressed as V
=VDD´(RB+RC)/(RA+RB+RC).
BH
If VDD is decreased so that V less than V
, the comparator output inverts
REF
from high to low, VOUT goes low, V turns on, RC is bypassed, and V
=VDD´RB/(RA+RB), which is less than
V
BL
V
By so doing, the comparator output will
BH.
stay low to prevent the circuit from oscillating when V
» V
B
REF.
If VDD falls below the minimum operating volt age, the output becomes undefined. When VDD goes from low to VDD´RB/(RA+RB) > V comparator output and VOUT goes high.
The detectable voltage is defined as:
RA RB RC
V
(-)=
DET
++
RB RC
+
The release voltage is defined as:
RA RB
(+) =
V
DET
+
RB
´ V
REF
in the following
REF
falls to a value
B
´ V
REF
is ex-
B
is high, M1
C
becomes:
B
REF
REF
, the
Conditions
Min. Typ. Max. Unit
6.65 7 7.35 V
6.783 7.35 8.085 V
V
OUT
=0.5V
0.05
V
DET
47
¾
V
0.02
DET
¾
2.1
510
0.1
V
24 V
The hysteresis width is:
V
HYS=VDET
(+) - V
DET
(-)
The figure demonstrates the NMOS output type with positive output polarity (VOUT is normally open, active low). The HT70XX series also supplies options for other output types
,
with active high outputs. Application circuits shown are examples of positive output polarity (normally open, active low) unless otherwise specified.
RA
C om parator
V
B
V
C
-
V
REF
RB
M1
RC
NMOS output voltage detector (HT70XXA)
DET
¾
Ta=25°C
V
mA
mA
V
DD
V
OUT
MN
V
SS
RL
7 May 3, 2000

Application Circuits

HT70XX
Microcomputer reset circuit
Normally a reset circuit is required to protect the microcomputer system from malfunctions due to power line interruptions. The following examples show how different output configura tions perform a reset function in various sys tems.
·
NMOS open drain output application for separate power supply
V
DD1
V
OUT
Micro -
HT70XXA
·
NMOS open drain output application with
RESET
computer
V
DD2
V
SS
R-C delay
V
DD
R
HT70XXA
V
OUT
Micro ­computer
Power-on reset circuit
With several external components, the NMOS open drain type of the HT70XX series can be used to perform a power-on reset function as shown:
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V
IN
R
C
D
V
DD
V
OUT
HT7044A
V
SS
V
DD
V
OUT
V
OUT
V
SS
t
C
V
SS
t
8 May 3, 2000
HT70XX
5V power line monitoring circuit
Generally, a minimum operating voltage of
4.5V is guaranteed in a 5V power line system. The HT7044A is recommended for use as 5V power line monitoring circuit.
·
5V power line monitor with power-on reset
5V Power line
R
C
D
V
DD
V
OUT
HT7044A
V
SS
·
with 5V voltage regulator
5V Voltage regulator
V
IN
HT1050
GND
5V
V
DD
V
SS
V
OUT
HT7044A
V
SS
Change of detectable voltage
If the required voltage is not found in the stan dard product selection table, it is possible to change it by using external resistance dividers or diodes.
·
Varying the detectable voltage with a resis tance divider
V
IN
RA
RB
V
SS
Detectable voltage =
Hysteresis width =
·
Varying the detectable voltage with a diode
V
IN
RA RB
Vf1
Vf2
V
DD
V
DD
HT70XXA
RA RB
+
RB
+
RB
´ V
V
OUT
V
V
´ V
OUT
SS
DET
HYS
HT70XXA
V
SS
V
SS
-
-
Detectable Voltage = V
f1+Vf2+VDET
9 May 3, 2000
HT70XX
Malfunction analysis
The following circuit demonstrates the way a circuit analyzes malfunctions by monitoring the variation or spike noise of power supply voltage.
V
DD
V
OUT
Charge monitoring circuit
The following circuit shows a charged monitor for protection against battery deterioration by overcharging. When the voltage of the battery is higher than the set detectable voltage, the transistor turns on to bypass the charge cur rent, protecting the battery from overcharging.
HT70XXA
V
SS
V
SS
Level selector
The following diagram illustrates a logic level selector.
V
DD
V
OUT
HT7039A
V
V
SS
V
DD
DET2
Solar Cell
V
OUT
HT7050A
V
DET1
-
V
DD
V
V
OUT
SS
Tr
BATT
HT70XXA
V
OUT
Load
5.0V
3.9V
V
DET1
V
DET2
V
OUT
t
t
10 May 3, 2000
HT70XX
Holtek Semiconductor Inc. (Headquarters)
No.3 Creation Rd. II, Science-based Industrial Park, Hsinchu, Taiwan, R.O.C. Tel: 886-3-563-1999 Fax: 886-3-563-1189
Holtek Semiconductor Inc. (Taipei Office)
5F, No.576, Sec.7 Chung Hsiao E. Rd., Taipei, Taiwan, R.O.C. Tel: 886-2-2782-9635 Fax: 886-2-2782-9636 Fax: 886-2-2782-7128 (International sales hotline)
Holtek Semiconductor (Hong Kong) Ltd.
RM.711, Tower 2, Cheung Sha Wan Plaza, 833 Cheung Sha Wan Rd., Kowloon, Hong Kong Tel: 852-2-745-8288 Fax: 852-2-742-8657
Copyright Ó 2000 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentionedherein are used solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable without further modification, nor recommends the use of its products for application that may pres ent a risk to human life due to malfunction or otherwise. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information, please visit our web site at http://www.holtek.com.tw.
11 May 3, 2000
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