Page 1
Ordering number: EN2119D
CMOS LSI
LC7461M
Infrared Remote Control Transmitter IC
Functions
.
32%3 function keys
.
13-bit custom codes
.
Operating supply voltage range VDD= 1.8 to 3.6 V
.
Supply current at the standby mode IDD= 1 µA or less
.
Double-press operation keys (no priority given)
.
On-chip oscillator (ceramic resonator : connected externally)
Package Dimensions
unit : mm
3045B-MFP24
[LC7461M]
Features
.
The custom code consists of 7 bits to be fixed by the
on-chip ROM and 6 bits being pin-settable. Sixty-four
custom codes may be selected externally (no diode required).
.
Minimum number of external parts required
SANYO : MFP24
Specifications
Absolute Maximum Ratings at Ta = 25°C
Parameter Symbol Conditions Ratings Unit
Maximum supply voltage V
Input voltage V
Output voltage V
Output current I
Allowable power dissipation Pd max Ta % 85°C 150 mW
Operating temperature Topr –40 to +85 °C
Storage temperature Tstg –50 to +125 °C
max V
DD
IN
OUT
OUT
DD
Each input pin VSS–0.3 to VDD+0.3 V
Each output pin VSS–0.3 to VDD+0.3 V
OUT –35 mA
VSS–0.3 to +5.5 V
Allowable Operating Conditions at Ta = 25°C
Parameter Symbol Pin Name Conditions min typ max Unit
Supply voltage V
Input high-level voltage V
Input low-level voltage V
Oscillation frequency f
DD
IH
IL
OSC
V
DD
KI0toKI3,
C
to C
0
KI0toKI3,
C
to C
0
f
= 455 kHz 1.8 3.0 3.6 V
OSC
0.7 V
5
5
DD
V
SS
400 455 500 kHz
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
O3096HA(II)/7058YT/6036KI,TS(KOTO) No.2119-1/7
0.3V
V
DD
DD
V
V
Page 2
LC7461M
Electrical Characteristics at Ta = 25°C, VDD= 3.0 V
Parameter Symbol Pin Name Conditions min typ max Unit
Operating supply
current
Quiescent supply
current
Output high-level
current
Output high-level
voltage
Output low-level
voltage
Output OFF-state
leakage current
Input high-level current I
Input low-level current I
Input floating voltage V
Input pull down
resistance
Internal Block Diagram
I
DD
I
DS
I
1 OUT VDD= 1.8 V, VOH= 1.0 V –8 mA
OH
I
2 OUT VDD= 3.0 V, VOH= 1.0 V –25 mA
OH
V
OH
V
OL
I
OFF
IH
IL
IF
R
IN
V
DD
V
DD
KO0toKO7IOH= –0.1 mA 0.3 V
OUT IOL= 0.1 mA 0.3 V
KO0toKO71µA
C0to C
C0to C
KI0toKI3 0.1 V
KI0toKI3 75 100 125 kΩ
Key ON, output: no load 1 mA
All keys OFF, OSC stop 1 µA
VIN=V
5
5
VIN=V
DD
SS
–1 µA
1µA
V
DD
Key
output
timing
signal
generator
Oscillator
Key
entry
circuit
Divider
Key data
register
Output
circuit
Decoder
Custom code
register
No.2119-2/7
Page 3
LC7461M
Pin Assignment
Top view
Pin Description
Pin Name Pin No. Input/Output Internal Equivalent Circuit Pin Function
V
DD,VSS
0toKO7 13 to 20 Output Key scan timing signal output pins
K
O
8, 12 Power supply pins VSS= GND
K
0toKI3 1 to 4 Input Keys return signal entry pins
I
Input/output pins for ceramic resonator-used
oscillation
OSC1
OSC2
C
to C
0
5
OUT 7 Output
TEST 9 Input
10
11
21 to 24,
5, 6
Input/output
Input
Oscillator configuration
Input pins for custom code setting
Capable of externally setting 6 bits of 13 bits in
all that provide a custom code
Output pin for transmit LED drive
LSI test pin
Normally set to high-level or brought to open
state
No.2119-3/7
Page 4
LC7461M
General Description of Function
1. Oscillator
Since a self-bias type amplifier of CMOS inverter is contained, an oscillator can be formed by connecting a ceramic
resonator.
To minimize power dissipation, the oscillator stops oscillating except when key operation is performed.
2. Key entry
Key entry pins K
0toKI3 and timing signal output pins KO0toKO7 provide a key matrix of 4 × 8 = 32.
I
Multi-press of key No. 20 and one of key No. 21, 22, 23 may be done, with no priority given in key entry. When the two
keys are kept pressed, a series of pulses will be output according to each key entry. If multi-press of keys which are not
allowed multi-press is done, no output will be delivered.
3. Data organization
Data consists of 42 bits in all: 13 bits of custom code, 8 bits of key data, and their inverted codes.
Custom code
13 bits
Custom code
13 bits
Key data Key data
8 bits
8 bits
No.2119-4/7
Page 5
(a) Custom code
The custom code, which consists of 13 bits (C
LC7461M
to C12) in all, is used to distinguish between receiving sets.
0
Pin-selectable
6 bits
C
to C12are fixed by the mask ROM and C0to C5are pin-settable.
6
In this example C0to C5are
set as follows:
C0C1C2C3C4C
011001
The custom codes are controlled by Sanyo to avoid duplication.
(b) Key data
KEY No.
28
29 10111000
30 01111000
31 11111000
D
0D1D2D3
0 00000000
1 10000000
2 01000000
3 11000000
4 00100000
5
.
.
.
1
0
.
.
.
0
1
.
.
.
.
.
.
0
1
D4D5D6D
0
0
.
.
.
1
0
.
.
.
1
0
7
0
.
.
.
0
.
.
.
.
.
.
0
0
Mask ROM
7 bits
5
Multi-press
KEY No.
20,2110101100
20,2201101100
20,2311101100
.
D
6,D7
D
0D1
may be preset to ‘‘0’’,‘‘1’’ beforehand (mask
D2D3D4D5D6D
option).
7
When multi-press of key No.20 and one of key No.21, 22, 23 is done, multi-bit D
in key entry.
(H: Key-ON state)
Key 20
data
transmit
Keys 20, 21
multi-press
data transmit
Key 21
data
transmit
Transmit
stop
Key 22
data
transmit
will be set to ‘‘1’’, with no priority given
5
Keys 20, 22
multi-press data
transmit
No.2119-5/7
Page 6
4. Transmit waveforms
The period of time shown below is for f
Leader code
LC7461M
= 455 kHz.
OSC
Custom code Custom code Key data Key data
13 bits
13 bits
8 bits
8 bits
.
First time
.
Second time onward (Transmission is available only when key entry continues.)
.
Carrier waveform
Carrier frequency = 1/12 f
OSC
7 38 kHz
No.2119-6/7
Page 7
Sample Application Circuit
Transmit
LED
LC7461M
In this example custom code C0to C5is C0zzzzzC5.
010101
No products described or contained herein areintendedforuse in surgical implants, life-support systems, aerospace equipment,
nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or
indirectly cause injury, death or property loss.
Anyone purchasing any products described or contained herein for an above-mentioned use shall:
1 Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors
and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and
expenses associated with such use:
2 Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO
ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally.
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume
production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use
or any infringements of intellectual property rights or other rights of third parties.
This catalog provides information as of October, 1996. Specifications and information herein are subject to change without notice.
No.2119-7/7
Loading...