RPM871
Photo Link Module
IrDA Infrared communication Module
RPM871
RPM871 is an infrared communication module for IrDA Ver. 1.2 (Low Power). The infrared LED, PIN photo diode, LSI are
all integrated into a single package. This module is designed with power down function and low current consumption at
stand-by mode. The ultra small package makes it a perfect fit for mobile devices.
Features
1) Applied to IrDA version 1.2. (Low Power)
2) Designed for low power consumption at waiting mode (Typ.73µA).
3) Suitable for sets driven by battery due to power down control function.
4) Power supply voltage range : 2.6V to 3.6V
5) Constant LED load resistance can change transmission distance. (Approx. 20 to 60cm)
Applications
Cellular phones, PDAs, etc.
Absolute maximum ratings
(Ta = 25°C)
Parameter
Power supply voltage
Power dissipation
Operating temperature range
Storage temperature range
LED peak current
Symbol
V
CC
Pd
Topr
Tstg
I
FP
Limits
−0.3
to
+7.0
150
∗1
−20
to
+85
−30
to
+100
200
∗2
Unit
V
mW
°C
°C
mA
∗1
70mm×70mm, t=1.6mm, glass epoxy mounting. Derating : 2mW/°C for operation above Ta=25°C
∗2
LED peak current<90µs. ON duty<20%
Recommended operating conditions
(Ta = 25°C)
Parameter
Power supply voltage
Symbol
V
CC
V
LEDA
Min.
2.6
2.6
Typ.
2.8
2.8
Max.
3.6
5.5
Unit
V
V
Rev.B
1/7
RPM871
Photo Link Module
Block diagram and application circuit
AMP
GND
1
2
NC
V
CC
V
CC
AMP
AMP
3
GND
GND
C1
4
POWER
DOWN
PWDOWN
PWDOWN
5
RXD
RXD
6
7
TXD
TXD
R1
(LEDV
CC
)
LEDA
LED
DRIVER
8
V
CC
(3pin) and VLEDA (8pin) can be used on
either common power source or different one.
Rev.B
2/7
RPM871
Photo Link Module
Terminal description
Pin No
1, 4
2
Terminal
GND
NC
Circuit
GND
This Terminal must be left open.
V
CC
For preventing from infection, connect
a capacitor between V
CC
(3pin) and
GND (4pin).
V
CC
Function
3
V
CC
5
PWDOWN
Power-down Control Terminal
H : POWERDOWN
L : OPERATION
CMOS Logic Level Input
When input is H, it will stop the receiving
circuit, Pin-PD current and transmitting
LED operation.
V
CC
PWDOWN
V
CC
300k
6
RXD
Receiving Data Output Terminal
CMOS Logic Level Output
When PWDOWN (5pin)=H, the RXD
output will be pulled up to V
CC
at
approximately 300kΩ.
V
CC
7
TXD
200K
Transmitting Data Input Terminal
H : LED (PWDOWN=L)
CMOS Logic Level Input
Holding TXD="H" status, LED will be
turn off approximately 45µs.
8
LEDA
LED
LED ANODE Terminal
Other power source can be used
difference between LEDV
CC
and V
CC
.
LED current depends on LED load
resistance value.
Rev.B
3/7
RPM871
Photo Link Module
Electrical characteristics
(Unless otherwise noted, V
CC
=2.8V, VLEDV
CC
=2.8V, Ta = 25°C)
Parameter
Consumption current1
Consumption current2
Transmission rate
PWDOWN INPUT High voltage
PWDOWN INPUT Low voltage
PWDOWN INPUT High current
PWDOWN INPUT Low current
<Transmitter>
TXD INPUT High voltage
TXD INPUT Low voltage
TXD INPUT High current
TXD INPUT Low current
LED ANODE current
<Receiver>
RXD OUTPUT High voltage
RXD OUTPUT Low voltage
RXD OUTPUT rise time
RXD OUTPUT fall time
RXD OUTPUT pulse width
Receiver latency time
VRXH
VRXL
tRR
tFR
twRXD
tRT
V
CC
−0.5
−
−
−
1.5
−
−
−
70
30
2.3
100
−
0.4
−
−
3.6
300
V
V
ns
ns
µs
µs
IRXH=−50µA
IRXL=200µA
C
L
=15pF
C
L
=15pF
C
L
=15pF,
2.4 to 115.2kbps
VTXH
VTXL
ITXH
ITXL
ILEDA
V
CC
−0.55
−
7
−1.0
−
−
−
14
0
144
−
0.55
28
1.0
−
V
V
µA
µA
mA
TXD=V
CC
[V]
TXD=0 [V]
R1=7.5 [Ω]
VPDH
VPDL
IPDH
IPDL
Symbol
I
CC
1
I
CC
2
Min.
−
−
2.4
V
CC
−0.55
−
−1.0
−1.0
Typ.
73
0.01
−
−
−
0
0
Max.
99
0.2
115.2
−
0.55
1.0
1.0
Unit
µA
µA
kbps
V
V
µA
µA
PWDOWN=V
CC
[V]
PWDOWN=0 [V]
Conditions
Waiting mode At no input light
PWDOWN PIN High At no input light
Optical characteristics
(Unless otherwise noted, V
CC
=2.8V, VLEDV
CC
=2.8V, Ta = 25°C)
Parameter
Peak wave length
Intensity1
Half-angle
Rise time / Fall time
Optical over shoot
Edge jitter
Minimum irradiance
Symbol
λP
IE1
θL/2
Tr/Tf
Min.
850
14.4
−
−
−
−40
−
500
±15
10
Typ.
870
36
±18
−
−
−
−
−
−
45
Max.
900
93.6
±30
100
25
40
6.8
−
−
96
Unit
nm
mW/Sr
deg
ns
%
ns
µW/cm
2
Conditions
−15°≤θ
L
≤15°
R1=7.5 [Ω]
10% to 90%
Tj
Eemin
−15deg ≤ θ
L
≤ +15deg
Maximum irradiance
INPUT Half-Angular
Maximum emitting time
Eemax
θD/2
TLEDmax
mW/cm
2
−15deg ≤ θ
L
≤ +15deg
deg
µs
TXD=V
CC
1. This product is not designed for protection against radioactive rays.
2. This product dose not include laser transmitter.
3. This product includes one PIN photo diode.
4. This product dose not include optical load.
Rev.B
4/7
RPM871
Photo Link Module
Timing chart
(Emitting side)
TXD
(7pin)
less than 45µs
more than 45µs
(emitting)
(emitting)
(emitting)
Internal LED
(Light output)
approximately 45µs
(Detecting side)
Light input
less than 2.3µs
more than 2.3µs
RXD
(6pin)
pull up to V
CC
at approximately 300kΩ
approximately 2.3µs
approximately 2.3µs
PWDOWN
(5pin)
Attached components
Recommended values
Part symbol
C1
Recommended value
1µF, tantalum or ceramic
Ex.) TCFGA1A105M8R (ROHM)
Notice
Bigger capacitance is recommended with much noise from power supply
More than 60cm distance, more than 4[µW/cm
2
] at detecting side.
(vs ver1.0)
More than 46cm distance, more than 6.8[µW/cm
2
] at detecting side.
(vs RPM871)
R1
7.5Ω±5%, 1/4W
(VLEDV
CC
=2.8V)
In case of using R1 with different condition from the above, formula is as follows :
LED resistance value : R1[Ω], LED average consumption current : ILED[mA], Supply voltage : VLEDV
CC
[V],
Link distance : d[cm] (Including LED’s distribution within
±15deg)
R1=T
×
(VLEDV
CC
−1.45)
/ d
2
−3.5
[Ω]
ILED=Duty
×
(VLEDVCC−1.36) / (R1+2.5) [A]
Duty : LED duty at emitting
T : 17300 (vs. RPM871), 29400 (vs. ver1.0)
∗
Please set up to be ILED / Duty
<
200[mA]
(Duty
<
20%)
Rev.B
5/7
微控制器 MCU
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