iC-LTA
preliminar y
Rev B1, Page 1/13
6-CH. INCREMENTAL OPTO ENCODER ARRAY
FEATURES
o
o
o
o
o
o
o
o
o
o
o
o
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o
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o
Monolithic photodiode array with excellent signal matching
Very compact size for small encoders
Moderate track pitch for relaxed assembly tolerances
Low noise signal amplifiers with high EMI tolerance
Single-pin programming of 3 operating modes:
analog, digital, and x2 interpolated
Analog signals for alignment and resolution enhancement
Selectable index gating: 1 T, 0.5 T (B-gated), 0.25 T (AB-gated)
Complementary outputs: A, B, Z and NA, NB, NZ
High output frequency for speedy drives and high resolution
U, V, W commutation signals, analog and digital
All outputs +/- 4 mA push-pull, current-limited and
short-circuit-proof
LED power control with 40 mA high-side driver
Single 3.5 V to 5.5 V operation, low power consumption
Operating temperature range of -40 °C to +110 °C (+120 °C)
Space saving optoQFN / optoBGA packages (RoHS compliant)
Custom made code disc and reticle designs on request
APPLICATIONS
o
Incremental encoder
o
Brushless DC motor
commutation
o
Industrial drives
PACKAGES
32-pin optoQFN
5 mm x 5 mm x 0.9 mm
15-pin optoBGA
6.2 mm x 5.2 mm x 1.7 mm
BLOCK DIAGRAM
+3.5..5.5V
C1
1μF
iC-LTA
PA
NA
PB
NB
PZ
NZ
POWER-ON RESET
TIP
TIN
SEL
LED
POWER
CONTROL
VCC
LED
PA
NA
PB
NB
PZ
D1
SIGNAL
COMPARATION
AND
QUADRATURE
OUTPUT
R1
47
INDEX
OUTPUT
NZ
T1
U
U
V
W
COMMUTATION
-
+
V
W
GND
CA
Copyright © 2010, 2013 iC-Haus
http://www.ichaus.com
iC-LTA
preliminar y
Rev B1, Page 2/13
6-CH. INCREMENTAL OPTO ENCODER ARRAY
DESCRIPTION
iC-LTA is a versatile optical sensor IC with integrated
photosensors whose signals are converted into volt-
ages by low-noise transimpedance amplifiers. Pre-
cise voltage comparators with hysteresis are used to
generate the digital signals, supplied to the output
pins via differential +/- 4 mA push-pull drivers.
The built-in LED power control with its 40 mA driver
stage permits a direct connection of the encoder
LED. Regardless of aging or changes in temperature
the received optical power is kept constant.
Selection input SEL chooses for three different op-
erating modes: regular A/B operation, A/B operation
with 2-fold interpolation, or analog operation. With
analog operation the amplified signal voltages are
available at the outputs for inspection and monitoring
encoder assembly.
The typical application of iC-LTA are incremental en-
coders for motor feedback and commutation. To this
end, iC-LTA provides a differential scanning for the
A/B track and the index track Z. The layout of the sig-
nal amplifiers is such that there is an excellent paired
channel matching, eliminating the needs for signal
calibration.
Additionally, three more tracks are provided to gener-
ate motor commutation information for the U, V and
W outputs, for instance with 120 degree phase shift
to operate 3-phase brushless motors (period count
and phase shift can be varied by the code disc ap-
plied).
iC-LTA
preliminar y
Rev B1, Page 3/13
6-CH. INCREMENTAL OPTO ENCODER ARRAY
PACKAGING INFORMATION
PAD LAYOUT
Chip size 2.88 mm x 3.37 mm
PAD FUNCTIONS
No. Name Function
See pin configuration.
MAX. WINDOW 1.900x3.120
1.156x0.228
1.108x0.238
1.064x0.248
0.800x0.330 (4x)
1.720x0.1503 (2x)
PA
NB
PZ
NZ
U
V
W
PB
NA
OUTSIDE TRACK "RA"
0.4401
0.5050
0.4500
0.4799
0.3797
1.3550 (*)
3.3700
0.4349
0.9200
2.8800
(*): VS. CENTER OF CHIP
iC-LTA
preliminar y
Rev B1, Page 4/13
6-CH. INCREMENTAL OPTO ENCODER ARRAY
PIN CONFIGURATION
oBGA LSH2C (6.2 mm x 5.2 mm)
PIN FUNCTIONS
No. Name Function
1
A
B
C
D
2
3
4
A2 VCC
A3 LED
A4
B1
B2
B3
B4
C1
C2
C3
C4
D1
D2
D3
GND
PA
NA
TIP
U
PB
NB
TIN
V
PZ
NZ
SEL
D4 W
+3.5..5.5 V Supply Voltage
LED Controller, High-Side Current
Source Output
Ground
Push-Pull Output A+ (Sin+)
Push-Pull Output A- (Sin-)
Positive Test Current Input
Push-Pull Output U
Push-Pull Output B+ (Cos+)
Push-Pull Output B- (Cos-)
Negative Test Current Input
Push-Pull Output V
Push-Pull Output Z+ (Index+)
Push-Pull Output Z- (Index-)
Op. Mode Selection Input:
lo = digital,
hi = x2 interpolated
open = analog (alignment)
Push-Pull Output W
For dimensional specifications refer to the relevant package data sheet, available separately.
iC-LTA
preliminar y
Rev B1, Page 5/13
6-CH. INCREMENTAL OPTO ENCODER ARRAY
PIN CONFIGURATION
oQFN32-5x5 (5 mm x 5 mm)
PIN FUNCTIONS
No.
Name Function
1 VCC
2 LED
+3.5..5.5 V Supply Voltage
LED Controller, High-Side Current
Source Output
Push-Pull Output A+ / Analog Sin+
1)
Push-Pull Output A- / Analog Sin-
Push-Pull Output B+ / Analog Cos+
Push-Pull Output B- / Analog Cos-
Push-Pull Output Z+ / Analog Z+
Push-Pull Output Z- / Analog Z-
Op. Mode Selection Input:
lo = digital
hi = x2 interpolated
open = analog (alignment aid)
Push-Pull Output W / Analog W
Negative Test Current Input
3)
Push-Pull Output V / Analog V
Positive Test Current Input
3)
Push-Pull Output U / Analog U
Index Length Selection Input:
lo = 0.5 T (B-gated),
hi = 1 T (ungated/T-gated),
open = 0.25 T (A and B-gated)
Ground
Backside Paddle
4)
32 31 30 29 28 27 26 25
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
24
23
22
21
20
19
18
17
3
4
5
6
7
8
9..16
17
PA
NA
PB
NB
PZ
NZ
n.c.
2)
SEL
18
19
20
21
22
23
W
TIN
V
TIP
U
T1
24 GND
25..32 n.c.
BP
1) Capacitive pin loads must be avoided when using the analog output signals.
2) Pin numbers marked n.c. are not in use.
3) The test pins TIP and TIN may remain unconnected.
4) The backside paddle may have a single link to GND. A current flow across the paddle is not permissible.
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