HOLTEK HT7704

HT7704
Touch Dimmer
Feature
•
•
•
•
•
•
•
•
Operating voltage: 4~10V
High noise immunity CMOS technology
High sensitivity and stability
Polarity insensitive with AC line
Minimal external components required
Loading range of sense input from 0 to 1000pf
•
50/60 Hz selectable
HT7704A: 3 steps control
HT7704B: 4 steps control
HT7704C: On/off switch
8 pin DIP/SOP package
General Description
The HT7704 series are CMOS LSIs in 8-lead DIP
package. They are designed to control the brightness of an incandescent lamp by changing the
triggering angles of the TRIAC with touch sense
input.
HT7704 is a selectable 3-step, 4-step or on/off
switch function dimmer. High sensitivity and
stability account for its eminent performance.
The sense input can sustain very heavy capacitive loading and propagate sense through a
highly resistive line. In addition, the application circuit is very simple.
Pin Assignment
Pad Assignment
Chip size: 1640 × 1620 (µm)2
* The IC substrate should be connected to VSS
in the PCB layout artwork.
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HT7704
Block Diagram
Unit: µm
Pad Coordinates
Pad No.
X
1
2
3
4
5
6
–563.75
–557.25
–563.75
–198.25
171.25
604.75
Y
373
166
–91
–544
–544
–297
Pad No.
X
7
8
9
10
11
604.75
594.25
595.25
–308.25
–641.75
Y
–122
230.5
544.5
573.5
573.5
Pin Description
Pin No. Pin Name I/O
Internal
Connection
Description
1
OSC
I
∗
2
ZC
I
CMOS
3
VDD
I
—
Power supply (positive)
4
SENSE
I
∗
Touch sense input
5
FB
I
∗
Feedback signal to control the sink current of the
SENSE pin.
For 50Hz or 60Hz AC signal selection input
It is connected to VSS when the AC line is 50Hz.
However, when the AC line is 60Hz, it is connected to
VDD. Refer to the application circuit for connection
details.
6
FSEL
I
CMOS
7
VSS
I
—
8
TRIG1
O
CMOS
Oscillator input
Line frequency 50Hz or 60Hz input for zero crossing
Power supply (negative)
Trigger output to drive the TRIAC
Low pulse output with a capacitor and resistors for
applications
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HT7704
Approximate internal connection circuit
Absolute Maximum Ratings
Supply Voltage ............................... –0.3V to 12V
Input Voltage..................VSS–0.3V to VDD+0.3V
Operating Temperature................... 0°C to 70°C
Storage Temperature................. –50°C to 125°C
(Ta=25°C)
Electrical Characteristics
Symbol
Parameter
Test Condition
VDD
Min.
Type
Max.
Unit
—
4
7
10
V
Condition
VDD
Operating Voltage
—
IDD
Operating Current
7V
*
—
200
400
µA
IIH
OPT1, OPT2 Input
High Current
7V
VIH=7V
—
40
80
µA
IOL1
TRIG1 Sink Current
7V
VOL=0.7V
0.4
0.7
—
mA
IOH1
TRIG1 Drive Current
7V
VOH=6.3V
–8
–14
—
mA
IOL2
TRIG2 Sink Current
7V
VOL=0.7V
6
11
—
mA
IOH2
TRIG2 Drive Current
7V
VOH=6.3V
–1
–2
—
mA
VIH
Input High Voltage
—
—
0.8VDD
—
—
V
VIL
Input Low Voltage
—
—
—
—
0.2VDD
V
FOSC
Operating Frequency
7V
—
400
—
KHz
ROSC=150KΩ
* The test conditions are shown below:
a. ZC is supplied by 60Hz/7V sinwave via 100KΩ.
b. FB is connected to VSS and SENSE, FSEL to VDD.
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HT7704
Functional Description
Selection table
There are 3 types of HT7704 and the following table illustrates their operating mode:
IC No.
OPT1
OPT2
Function
HT7704A
Open
Open
3 steps of controllable brightness
HT7704B
Open
Bond to VDD
4 steps of controllable brightness
HT7704C
Bond to VDD
Open
On/off the light
Flow Chart
• 3 steps (for the HT7704A)
• 4 steps (for the HT7704B)
The first touch turns the light on at it’s initial
brightness level. The second touch makes the
light a little brighter. The light is the brightest by
the third touch. Finally, the fourth touch turns
the light off.
Similarly with the 4-step. The first touch tuns
the light on at it’s initial brightness level. The
second touch makes the light brighter. The
brightness increases greatly on the third
touch and reaches it’s brightest on the fourth
touch, respectively. Finally the fifth touch
switches the light off.
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HT7704
• ON/OFF switch (for the HT7704C)
The initial touch turns the light on. When touched again, the light is turned off, and so on.
Timing Diagram
3 steps trigger angle (FOSC=400KHz)
T RIAC turns off
T RIAC turns on
T RIAC
(T rigger angle=120.96°)
T RIG1
T RIG2
T RIAC
(T rigger angle=86.4°)
T RIG1
T RIG2
T RIAC
(T rigger angle=17.28°)
T RIG1
T RIG2
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HT7704
4 steps trigger angle (FOSC=400KHz)
T RIAC turns off
T RIAC turns on
T RIAC
(T rigger angle=129.6°)
T RIG1
T RIG2
T RIAC
(T rigger angle=95.04°)
T RIG1
T RIG2
T RIAC
(T rigger angle=69.12°)
T RIG1
T RIG2
T RIAC
(T rigger angle=17.28°)
T RIG1
T RIG2
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HT7704
On/off trigger angle (FOSC=400KHz)
T RIAC
(T rigger angle=17.28°)
T RIG1
T RIG2
Application Circuit
Package form
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