LT1341_15 Datasheet, PDF (1/8 Pages) Linear Technology – 5V RS232 Transceiver with One Receiver Active in Shutdown

LT1341
5V RS232 Transceiver with One
Receiver Active in Shutdown
FEATURES
s _{One Receiver Remains Active While in Shutdown}
s _{ESD Protection Over ±10kV}
s _{Uses Small Capacitors: 0.1µF, 0.2µF}
s _{60µA Supply Current in Shutdown}
s _{Pin Compatible with LT1137A}
s _{120kBaud Operation for RL = 3k, CL = 2500pF}
s _{250kBaud Operation for RL = 3k, CL = 1000pF}
s _{CMOS Comparable Low Power: 60mW}
s _{Operates from a Single 5V Supply}
s _{Easy PC Layout: Flowthrough Architecture}
s _{Rugged Bipolar Design}
s _{Outputs Assume a High Impedance State When}
Off or Powered Down
s _{Absolutely No Latchup}
s _{Available in SSOP Package}
APPLICATI S
s _{Notebook Computers}
s _{Palmtop Computers}
DESCRIPTIO
The LT^®1341 is an advanced low power three-driver, five-
receiver RS232 transceiver. Included on the chip is a
shutdown pin for reducing supply current to near zero.
During shutdown one receiver remains active to detect
incoming RS232 signals, for example, to wake up a
system. All other receivers and the drivers assume high
impedance states during shutdown.
The driver disable function provides additional control of
operating mode. When driver disable is high the charge
pump and drivers turn off. Receivers continue to operate
during driver disable.
New ESD structures on the chip allow the LT1341 to
survive multiple ±10kV strikes, eliminating the need for
costly TransZorbs^® on the RS232 line pins.
The LT1341 is fully compliant with all EIA RS232 specifi-
cations and operates in excess of 120kbaud even driving
heavy capacitive loads.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TransZorb is a registered trademark of General Instruments, GSI
TYPICAL APPLICATI
V⁺ 1
0.1µF
V_CC
2
3
2 × 0.1µF
4
TO LINE
DRIVER 1 OUT ⁵
6
RX1 IN
DRIVER 2 OUT ⁷
RX2 IN ⁸
RX3 IN ⁹
RX4 IN ¹⁰
11
DRIVER 3 OUT
RX5 IN (LOW-Q) ¹²
ON/OFF ¹³
NC ¹⁴
LT1341
28 V ^–
27
0.1µF
26
2 × 0.1µF
25 _{DRIVER 1 IN}
24 _{RX1 OUT}
23 _{DRIVER 2 IN}
22 _{RX2 OUT}
21 _{RX3 OUT}
20 _{RX4 OUT}
19
DRIVER 3 IN
18 _{RX5 OUT (LOW-Q)}
17
GND
16
DRIVER DISABLE
15 _NC
TO LOGIC
RING DETECT IN
µCONTROLLER
OR
µPROCESSOR
SHUTDOWN
CONTROL OUT
LT1341 • TA01
RECEIVER
OUTPUT
C_L = 50pF
DRIVER
ROUTPUT
R_L = 3k
C_L = 2500pF
INPUT
Output Waveforms
LT1341 • TA02
1