ELECTRICAL CHARACTERISTICS

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

CONTROL INPUT ADRM

Input Voltage Low

V

Input Voltage High

V

Input Current Low

(switched P and N

channel pull-up/pull down)

-10

-100

-100

-600

µA

µA

Input Current High

(switched P and N

channel pull-up/pull down)

10

100

100

600

µA

µA

DATA OUTPUT REMO

Output Current High

70

80

80

mA

mA

mA

Output Current Low

0.6

0.6

mA

mA

Pulse Length

1

msec

OSCILLATOR

Input Current

5

5

7

µA

µA

Output Voltage high

V

Output Voltage Low

0.7

V

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