
ELECTRICAL CHARACTERISTICS
T
amb
= 25
o
C, unless otherwise specified
Symbol
CONTROL INPUT ADRM
V
IL
Input Voltage Low
V
IH
Input Voltage High
I
IL
Input Current Low
(switched P and N
channel pull-up/pull down)
I
IH
Input Current High
(switched P and N
channel pull-up/pull down)
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
0.3 x V
DD
V
V
0.7 x V
DD
Pull-up Act. Oper. Condition, V
IN
= V
SS
V
DD
= 2V
V
DD
= 6.5V
Pull-down Act. Stand-by Cond.,V
IN
= V
DD
V
DD
= 2V
V
DD
= 6.5V
-10
-100
-100
-600
μ
A
μ
A
10
100
100
600
μ
A
μ
A
DATA OUTPUT REMO
- I
OH
Output Current High
V
DD
= 2.5V, V
OH
= 0.8V, T
A
= 70
o
C
V
DD
= 2.5V, V
OH
= 0.8V, T
A
= 25
o
C
V
DD
= 6.5V, V
OH
= 5V
V
DD
= 2V, V
= 0.4V
V
DD
= 6.5V, V
OL
= 0.4V
V
DD
= 6.5V, Oscill. Stopped
70
80
80
0.6
0.6
mA
mA
mA
mA
mA
msec
I
OL
Output Current Low
t
OH
Pulse Length
1
OSCILLATOR
I
I
Input Current
OSCI at V
DD
V
DD
= 2V
V
DD
= 6.5V
5
5
7
μ
A
μ
A
V
V
V
OH
V
OL
Output Voltage high
Output Voltage Low
V
DD
= 6.5V, - I
OH
= 0.1mA
V
DD
= 6.5V, I
OL
= 0.1mA
V
DD
- 0.8
0.7
3
I - INPUTS AND OUTPUTS
I.1 - Key Matrix Inputs and Outputs
(DRV0N to
DRV6N and SEN0N to SEN6N)
The transmitter keyboard is arranged as a scanned
matrix. The matrix consists of 7 driver ouputs and
7 sense inputs. The driver outputs DRV0N to
DRV6N are open drain N-channel transistors and
they are conductive in the stand-by mode. The 7
sense inputs (SEN0N to SEN6N) enable the gen-
eration of 56 command codes. With 2 external
diodes all 64 commands are addressable. The
sense inputs have P-channel pull-up transistors so
that they are HIGH until they are pulled LOW by
connecting them to an output via a key depression
to initiate a code transmission. The codes for the
selected key are given in Table 1.
I.2 - Address Mode Input
(ADRM)
The sub-system address and the transmission
mode are defined by connecting the ADRM input
to one or more driver outputs (DRV0N to DRV6N)
of the key matrix. If more than one driver is con-
nected to ADRM, they must be decoupled by di-
odes. This allows the definition of seven
sub-system addresses as shown in Table 2.
The ADRM input has switched pull-up and pull-
down loads. In the stand-by mode only the pull-
down device is active. Whether ADRM is open
(sub-system address 0) or connected to the driver
outputs, this input is LOW and will not cause un-
wanted dissipation. When the transmitter becomes
active by pressing a key, the pull-down device is
switched-off and the Pull-up device is switched-on,
so that the applied driver signals are sensed for the
decoding of the sub-system address and the mode
of transmission.
The arrangement of the sub-system address cod-
ing is such that only the driver DRVnN with the
highest number (n) defines the sub-system ad-
dress, e.g. in mode B, if drivers DRV2N and DRV4N
are connected to ADRM, only DRV4N will define
the sub-system address. This option can be used
in systems requiring more than one sub-system
address. The transmitter may be hard-wire for sub-
system address 2 by connecting DRV1N to ADRM.
If now DRV3N is added to ADRM by a key or a
switch, the transmitted sub-system address
changes to 4. A change of the sub-system will not
start a transmission.
I.3 - Remote Control Signal Output
(REMO)
The REMO signal output stage is a push-pull type.
In the HIGH state, a bipolar emitter-follower allows
a high output current. The timing of the data output
format is listed in Figures 1 and 2.
STV3012
3/8