TSL1406R, TSL1406RS
768
×
1 LINEAR SENSOR ARRAY WITH HOLD
TAOS042D
−
APRIL 2007
Terminal Functions
TERMINAL
NAME
AO1
AO2
CLK1
CLK2
GND
HOLD1
HOLD2
SI1
SI2
SO1
SO2
V
DD
V
PP
NO.
6
12
4
10
5
3
9
2
8
7
11
13
1
I
I
I
I
O
O
I/O
O
O
I
I
Analog output, section 1.
Analog output, section 2.
Clock, section 1. CLK1 controls charge transfer, pixel output, and reset.
Clock, section 2. CLK2 controls charge transfer, pixel output, and reset.
Ground (substrate). All voltages are referenced to GND.
Hold signal. HOLD1 shifts pixel data to parallel buffer. HOLD1 is normally connected to SI1 and HOLD2 in
serial mode, SI1 in parallel mode.
Hold signal. HOLD2 shifts pixel data to parallel buffer. HOLD2 is normally connected to SI2 in parallel mode.
Serial input (section 1). SI1 defines the start of the data-out sequence.
Serial input (section 2). SI2 defines the start of the data-out sequence.
Serial output (section 1). SO1 provides a signal to drive the SI2 input in serial mode.
Serial output (section 2). SO2 provides a signal to drive the SI input of another device for cascading or as an
end-of-data
indication.
Supply voltage for both analog and digital circuitry.
Normally grounded.
DESCRIPTION
Detailed Description
The sensor consists of 768 photodiodes, called pixels, arranged in a linear array. Light energy impinging on a
pixel generates photocurrent that is then integrated by the active integration circuitry associated with that pixel.
During the integration period, a sampling capacitor connects to the output of the integrator through an analog
switch. The amount of charge accumulated at each pixel is directly proportional to the light intensity on that pixel
and the integration time.
The output and reset of the integrators are controlled by a 384-bit shift register and reset logic. An output cycle
is initiated by clocking in a logic 1 on SI. Another signal, called HOLD, is generated from the rising edge of SI1
when SI1 and HOLD1 are connected together. This causes all 384 sampling capacitors to be disconnected from
their respective integrators and starts an integrator reset period. As the SI pulse is clocked through the shift
register, the charge stored on the sampling capacitors is sequentially connected to a charge-coupled output
amplifier that generates a voltage on analog output AO. The integrator reset period ends 18 clock cycles after
the SI pulse is clocked in. Then the next integration period begins. On the 384
th
clock rising edge, the SI pulse
is clocked out on the SO1 pin (section 1) and becomes the SI pulse for section 2 (when SO1 is connected to
SI2). The rising edge of the 385
th
clock cycle terminates the SO1 pulse, and returns the analog output AO of
section 1 to high-impedance state. Similarly, SO2 is clocked out on the 768
th
clock pulse. Note that a 769
th
clock
pulse is needed to terminate the SO2 pulse and return AO of Section 2 to the high-impedance state. If a minimum
integration time is desired, the next SI pulse may be presented after a minimum delay of t
qt
(pixel charge transfer
time) after the 769
th
clock pulse. Sections 1 and 2 may be operated in parallel or in serial fashion.
Copyright
E
2007, TAOS Inc.
r
r
The
LUMENOLOGY
r
Company
2
www.taosinc.com
TAOS [ TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS ]
