Cmsemicon SC7020 Series User manual

SC7020x User Manual
Low power single touch single output IC
Rev. 1.1
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SC7020x
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Rev. 1.1
Manual
1. PRODUCT DESCRIPTION ...................................................................................................3
2. CHARACTERISTIC...............................................................................................................3
3. PRODUCT SPECIFICATION ................................................................................................3
4. SYSTEM STRUCTURE DIAGRAM.......................................................................................4
5. PACKAGING AND PIN DESCRIPTION................................................................................5
5.1 SC70201, SC70202 Pin Diagram ..............................................................................................................................5
5.2 SC70205 Pin Diagram................................................................................................................................................6
6. FUNCTION DESCRIPTION...................................................................................................7
6.1 Output Mode and Pad Option .....................................................................................................................................7
6.2 Maximum output time of key.......................................................................................................................................7
6.3 Low Power Mode ........................................................................................................................................................7
6.4 Sensitivity adjustment .................................................................................................................................................8
7. APPLICATION CIRCUIT.......................................................................................................9
8. ELECTRICAL CHARACTERISTICS...................................................................................10
8.1 Limit Parameters of Electrical Characteristics...........................................................................................................10
8.2 DC Characteristics....................................................................................................................................................10
9. PACKAGING.......................................................................................................................11
9.1 SOT23-6 ...................................................................................................................................................................11
10. VERSION REVISION..................................................................................................12

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SC7020x
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Rev. 1.1
1. Product Description
SC7020x is a touch pad detector IC which offers 1 touch key. The device built-in voltage regulator
circuit to provide a stable voltage for the touch sensing circuit, while the internal integration of efficient and
perfect touch detection algorithm, so that the chip has a stable touch detection effect. The touching
detection IC is designed for replacing traditional direct button key with wide operating voltage and low power
consumption, which can widely meet the needs of different consumer applications
2. Characteristic
◆Working voltage: 2.4~5.5V
◆Working temperature: -40~85℃
◆Excellent anti-interference performance: built-in voltage regulator circuit, power-on reset, low-voltage
reset function and environment adaptive algorithm and other measures
◆Low power standby current: Typical value 0.8uA@VDD=3V/no load
◆The key response time max about 220mS at low power mode @VDD=3V
◆Sensitivity can adjust by the capacitance（3~50pF）outside
◆Output type selection（TOG）: synchronous output or toggle output
◆Output optional CMOS output (QC) or Open drain output (QD)
◆Maximum output time of key: 8 s/16 s/64s~ infinity（±30%）
◆After power-on have about 0.4s stable-time, during the time do not touch the key pad, and the
function is disabled
◆the function is disabled HBM ESD: more than 5KV
◆Packaging: SOT23-6
3. Product Specification
Maximum output time
Output type
Product
infinity
16s
8s
64s
Push-pull
output
Open drain
output
SC70201
■
■
SC70202
■
■
SC70205
■
■

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SC7020x
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Rev. 1.1
4. System Structure Diagram
Sensor
oscillator circuit
Sensor &
Reference
detecting circuit
Timing counter
& function
option control
circuit
System
oscillator circuit
Regulator
circuit
Touch
detecting circuit
Key-on &
Timing control
Output &
Driver circuit
TK
QC/QD
TOG
AHLB

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SC7020x
www.mcu.com.cn
Rev. 1.1
5. Packaging and Pin Description
5.1 SC70201, SC70202 Pin Diagram
SC70201
SC70202
1
2
3
QC
GND
TK
TOG
VDD
AHLB
6
5
4
Pin Description:
Pad
NO
Pin name
I/O type
description
1
QC
O
CMOS output pin
2
GND
P
Negative power supply, ground
3
TK
I
Touch key sensor input pin
4
AHLB
I-PL
Output QC active high or low selection
0(Default):Active high; 1:Active low
5
VDD
P
Positive power supply
6
TOG
I-PL
Output type selection 0 (Default): synchronous output; 1: toggle output
Pin Type:
◆I
CMOS input
◆P
Power／Ground
◆O
CMOS output
◆I-PH
CMOS input and pull-high resister
◆I/O
CMOS I/O
◆I-PL
CMOS input and pull-low resister

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SC7020x
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Rev. 1.1
5.2 SC70205 Pin Diagram
SC70205
1
2
3
QD
GND
TK
TOG
VDD
AHLB
6
5
4
Pin Description:
Pad
NO
Pin name
I/O type
description
1
QD
OD
Open drain output pin
2
GND
P
Negative power supply, ground
3
TK
I
Touch key sensor input pin
4
AHLB
I-PL
Output QC active high or low selection
0(Default):Active high; 1:Active low
5
VDD
P
Positive power supply
6
TOG
I-PL
Output type selection 0 (Default): synchronous output; 1: toggle output
Pin Type:
◆I
CMOS input
◆P
Power／Ground
◆OD
Open drain output
◆I-PH
CMOS input and pull-high resister
◆I/O
CMOS I/O
◆I-PL
CMOS input and pull-low resister

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SC7020x
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Rev. 1.1
6. Function Description
6.1 Output Mode and Pad Option
The AHLB and TOG pads are latches: The default status is low. If the pads are connected to VDD
before power-on, the status changes to high after power-on, and no current leakage occurs.
TOG pad: Synchronous output or toggle output selection.
AHLB pad: Output CMOS active high or active low selection.
Pad QC (CMOS output) option features:
TOG
AHLB
Pad QC/QD features
0
0
Synchronous output, CMOS active high
0
1
Synchronous output, CMOS active low
1
0
Toggle output, power on state = 0
1
1
Toggle output, power on state = 1
6.2 Maximum output time of key
Objects covering the touchpad or sudden changes in the environment may cause touch detection to
remain active. The system will return to the initial state of power-on and the output will become invalid, when
the IC's internal touch algorithm detects that the output valid duration reaches the set value of 8s/16s/64s
(±30%).
6.3 Low Power Mode
SC7020x in the Low Power mode it will be saving power. In this mode when detecting key touch, it will
switch to Fast mode. Until the key touch is released and will keep a time about 10 s. Then it returns to Low
Power mode.
Low Power
mode timing Fast mode timing Low Power
mode timing Fast mode timing Low Power
mode timing
-125ms -16ms -125ms -16ms ABOUT 10 SEC -125ms
POSSIBLE KEY TOUCH KEY RELEASE
(NOT REALLY TOUCH) KEY TOUCH KEY RELEASE
QCVDD
VSS
TK VDD
VSS

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SC7020x
www.mcu.com.cn
Rev. 1.1
6.4 Sensitivity adjustment
The equivalent capacitance on the IC touch pad will affect the sensitivity. So the sensitivity adjustment
must according to the practical application on PCB. The SC7020x offers some methods for adjusting the
sensitivity outside.
1) By the touchpad size: Under other conditions are fixed. Using a larger touchpad size can increase
sensitivity. Otherwise it can decrease sensitivity. But the touchpad size must use in the effective
scope.
2) By the panel thickness: Under other conditions are fixed. Using a thinner panel can increase
sensitivity. Otherwise it can decrease sensitivity.
3) By the value of Cs: Under other conditions are fixed. When the touchpad is not use the Cs to GND,
the sensitivity is most sensitive. When adding the value of Cs will reduce sensitivity in the useful
range（3≦Cs≦50pF）.

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SC7020x
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Rev. 1.1
7. Application circuit
1
2
3
QC/QD
GND
TK
TOG
VDD
AHLB
6
5
4VDD
VDD VDD
C1
0.1uF
GND
GND
GND
R2 0
Cs
TP1
SC7020x
Q
Figure 7-1: Schematic diagram of the circuit
Note:
1) On PCB, the length of lines from touch pad to IC pin shorter is better. And the lines do not parallel
and cross with other lines.
2) The power supply must be stable. If the supply voltage drift or shift quickly, maybe causing
sensitivity anomalies or false detections.
3) The material of panel covering on the PCB can not include the metal or the electric element. The
paints on the surfaces are the same.
4) The C1 capacitor (104 or larger) must be used between VDD and GND; and should be routed with
very short tracks to the device’s VDD and GND pins.
5) The capacitance Cs can be used to adjust the sensitivity. The value of Cs uses smaller, then the
sensitivity will be better. The sensitivity adjustment must according to the practical application on
PCB. The range of Cs value are 3~50pF.
6) The sensitivity adjustment capacitors（Cs）must use smaller temperature coefficient and more
stable capacitors. Such are X7R, NPO for example. So for touch application, recommend to use
NPO capacitor, for reducing that the temperature varies to affect sensitivity.

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SC7020x
www.mcu.com.cn
Rev. 1.1
8. Electrical Characteristics
8.1 Limit Parameters of Electrical Characteristics
Limit Parameters
Parameter
Symbol
Conditions
Rating
Unit
Supply Voltage
VDD
-
-0 to +5.5
V
Input Voltage
VI
All I/O port
-0.3 to VDD+0.3
V
Working temperature
TA
-
-40~ +85
℃
Storage Temperature
TSTG
-
-50~ +125
℃
Human Body Mode
ESD
5
KV
8.2 DC Characteristics
（VDD=2.0V~5.5, TA= 25℃, unless otherwise indicated）
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Working voltage
VDD
2.4
3
5.5
V
Internal Regulator Output
VREG
2.0
2.2
2.4
V
High level input voltage
VIH
0.75
1.0
VDD
Low level input voltage
VIL
0
0.25
VDD
Output Port Source Current
IOH
VDD=3V, VOH=2.1V
-9
mA
Output Port Sink Current
IOL
VDD=3V, VOL=0.9V
25
mA
Input Pin Pull-low Resistor
RPL
VDD=3V（TOG, AHLB）
55K
ohm
Output Response Time
TR
VDD=3V, At fast mode
20
ms
VDD=3V, At low power mode
200
Working current
ISB
VDD=3V, At low power mode
(no load)
0.8
1.5
μA
VDD=3V, At fast mode(no load)
1.6
3

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SC7020x
www.mcu.com.cn
Rev. 1.1
9. Packaging
9.1 SOT23-6
Symbol
Millimeter
Min
Nom
Max
A
-
-
1.25
A1
0.04
-
0.10
A2
1.00
1.10
1.20
A3
0.55
0.65
0.75
b
0.38
-
0.48
b1
0.37
0.40
0.43
c
0.11
-
0.21
c1
0.10
0.13
0.16
D
2.72
2.92
3.12
E
2.60
2.80
3.00
E1
1.40
1.60
1.80
e
0.95BSC
e1
1.90BSC
l
0.30
-
0.60
θ
0
-
8°

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SC7020x
www.mcu.com.cn
Rev. 1.1
10. Version Revision
Version number
Time
Revised content
V1.0
May, 2020
Original version
V1.1
Dec, 2021
Delete some chip products