7
LT1130A/LT1140A Series
CC
HARA TERISTICS
UW
A
TYPICALPERFOR
CE
Shutdown to Driver Output
Receiver Short-Circuit Current
Driver Short-Circuit Current
Driver Output Waveforms
LT1137A TPC12
10
5
0
–10
–5
DRIVER OUTPUT
RL = 3k
CL = 2500pF
INPUT
DRIVER OUTPUT
RL = 3k
PI FU CTIO S
U
UU
VCC: 5V Input Supply Pin. Supply current drops to zero in
the shutdown mode. This pin should be decoupled with a
0.1
F ceramic capacitor close to the package pin. Insuffi-
cient supply bypassing can result in low output drive levels
and erratic charge pump operation.
GND: Ground Pin.
ON/OFF: Control the operation mode of the device and is
TTL/CMOS compatible. A logic low puts the device in the
shutdown mode which reduces input supply curent to zero
and places all of the drivers and receivers in high imped-
ance state. A logic high fully enables the transceiver.
DRIVER DISABLE: This pin provides an alternate control
for the charge pump and RS232 drivers. A logic high on
this pin shuts down the charge pump and places all drivers
in a high impedance state. Receivers remain active under
these conditions. Floating the DRIVER DISABLE pin or
driving it to a logic low level fully enables the transceiver.
A logic low on the ON/OFF pin supersedes the state of the
DRIVER DISABLE pin. Supply current drops to 4mA when
in driver disable mode.
V+: Positive Supply Output (RS232 Drivers). V+
≈ 2VCC –
1.5V. This pin requires an external charge storage capaci-
tor C
≥ 1.0F, tied to ground or VCC. Larger value capaci-
tors may be used to reduce supply ripple. With multiple
transceivers, the V + and V – pins may be paralleled into
common capacitors. For large numbers of transceivers,
increasing the size of the shared common storage capaci-
tors is recommended to reduce ripple.
TEMPERATURE (°C)
–55
SHORT-CIRCUIT
CURRENT
(mA)
20
25
30
25
75
LT1137A TPC10
15
10
–25
0
50
100
125
5
0
ISC+
ISC –
TEMPERATURE (°C)
–55
0
SHORT-CIRCUIT
CURRENT
(mA)
20
50
0
50
75
LT1137A TPC11
10
40
30
–25
25
100
125
ISC+
ISC–
LT1137A TPC13
DRIVER
OUTPUT HIGH
RL = 3k
ON/OFF PIN
DRIVER
OUTPUT LOW
RL = 3k