FEATURES
MX172
TRIANGULAR TYPE AUTO FOCUS IC
• Package : 14-pin SSOP
• Operating voltage : 2V~4V
• Operating temperature : -25
o
C~60oC
• Supply current : max. 10mA (without output current)
• Input current level : 1nA~5uA
DESCRIPTION
MX172 is designed for Triangular system auto focus
cameras. It is regarded as input component for PSD
(Position Sensitive Diode), and comprises of circuits that
drive AF magnet as output, an infrared emission diode
current control circuit, and control circuit of sequential
timing.
PIN CONFIGURATION
14 SSOP
14
GND
CH1
PSD1
PSD2
CH2
VCC
VE
2
3
4
MX172
5
6
7
OUT1
13
OUT2
12
IRED
11
CTRL
10
CT
9
VR1
8
VR2
• Surround light level : max. 50uA (PSD output current)
• IRED drive output : min. 20mA
• Magnet drive current : min. 200mA
• Measuring time : max. 50ms
PIN FUNCTIONS
SYMBOL PIN NAME
GND Ground Pin
CH1 Hold Capacitor Pin 1
PSD1 PSD Input Pin 1
PSD2 PSD Input Pin 2
CH2 Hold Capacitor Pin 2
VCC Supply Pin (Secondly)
VE Supply Pin (Battery)
VR2 VR Pin for Adjustment 2
VR1 VR Pin for Adjustment 1
CT Timing Capacitor
CTRL Power Control
IRED Output Control for IRED
OUT2 Data Output Pin 2 (MSB)
OUT1 Data Output Pin 1(LSB)
P/N: PM0168
1
REV. 2.1, AUG 29, 1995
BLOCK DIAGRAM
MX172
VR1 VR2
GND
CH1
PSD1
PSD2
CH2
Vcc
Surrounding light
Head Amp.1
Head Amp.2
Surrounding light
BASIC CONNECTION DIAGRAM
rejection 1
rejection 2
Switch
AF Adjust
Inf.Cramp
Operation
Sequence Control Logic
CTLR
Comparator
Latch
and
Encode
IRED Drive Circuit
Timing Circuit
C Timing
Output
Driver
Output1, 2
IRED
VE
P/N: PM0168
OUT1
OUT2
IRED
CTRL
VR1
VR2
14
13
12
11
10
IRED
R3
SW1
C4
m
0.022 F
9
VR2
VR1
8
REV. 2.1, AUG 29, 1995
GND
1
CH1
PSD
2
3
4
5
6
7
PSD1
PSD2
CH2
VCC
VE
C TIMING
C1
C2
0.47 F
C3
0.47 F
m
m
2
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