LT1319CS Linear Technology, LT1319CS Datasheet - Page 4

• Manufacturer Part Number: LT1319CS
• Description: IC RCVR BUILDING BLOCK IR 16SOIC
• Manufacturer: Linear Technology
• Type: Receiverr

Specifications of LT1319CS

• Number Of Drivers/receivers: 0/1
• Protocol: Infrared (IRDA)
• Voltage - Supply: 5V
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

LT1319
TYPICAL PERFORMANCE CHARACTERISTICS
CIRCUIT DESCRIPTIO
The LT1319 is a general purpose low noise, high speed,
high gain, infrared receiver designed to easily provide IR
communications with portable computers, PDAs, desktop
computers and peripherals. The receiver takes the photo-
current from an infrared photodiode (Siemens BPW34FA
or Temic BPV22NF) and performs a current-to-voltage
conversion. After external filtering that is tailored for the
desired communication standard, two filter buffers are
provided. There are dual gain chains with nominal gain of
400V/V that feed internal comparators with hysteresis. The
comparator thresholds are set externally with a current into
the V
time of 25ns and is well-suited to high data rates.
4
250
200
150
100
50
–1
–2
–3
–4
–5
0
5
4
3
2
1
0
100k
10k
TH
Preamp Frequency Response vs
Input Capacitance
Preamp Output Noise vs
Input Capacitance
T
T
pin. The high frequency comparator has a response
A
A
= 25°C
= 25°C
100k
1M
FREQUENCY (Hz)
FREQUENCY (Hz)
10pF
50pF
1M
50pF
10M
30pF
30pF
10pF
10M
W
1319 G01
1319 G04
100M
U
100M
U
1000
100
0.1
10
20
15
10
1
5
0
100
0.1
Input-Referred Noise vs
Lowpass Filter on PREOUT
Preamp Highpass vs
Capacitance on FILT1
T
R
A
HIGHPASS CORNER FREQUENCY (Hz)
FILTER
= 25°C
FILTER CUTOFF FREQUENCY (MHz)
1k
= 1k
10k
The low frequency comparator responds in 60ns and is
useful for more modest data rates such as Sharp/Newton
and IRDA-SIR. The circuit also contains shutdown circuitry
to reduce power consumption. Rejection of ambient inter-
ference is accomplished with AC coupling loops around the
preamp and the two gain stages. The rejection frequency is
set with an internal resistor and an external capacitor to
ground. This feature allows changing of the break fre-
quency by simply switching in additional capacitors. To aid
in rejection of power supply noise there is internal supply
regulation and a fully differential topology after the filter
buffers.
1
100k
T
A
= 25°C
1319 G02
1319 G05
1M
10
1000
100
1.0
0.9
0.8
0.7
0.6
0.5
10
1
1k
20
Gain Stage Highpass vs
Capacitance on FILT2 or FILT2L
FILTIN- or FILTINL- Referred
Threshold Voltage vs R
HIGHPASS CORNER FREQUENCY (Hz)
10k
R
100k
T1
30
(kΩ)
T1
1M
T
T
A
A
= 25°C
= 25°C
1319 G03
1319 G06
1319fb
10M
40