±15 kV ESD protected 3 to 5.5 V, 400 kbps,
RS-232 transceiver with auto-power-down
Features
■ ESD protection for RS-232 I/O pins:
±8 kV IEC 1000-4-2 contact discharge
±15 kV human body model
■ 1 µA supply current achieved when in auto-
power-down
■ 250 kbps minimum guaranteed data rate
■ Guaranteed 6 V/ms slew rate range
■ Guaranteed mouse drive ability
■ 0.1 µF external capacitors
■ Meets EIA/TIA-232 specifications down to 3 V
■ Available in SSOP-28 package
Description
The ST3241E device consists of 3 drivers, 5
receivers and a dual charge-pump circuit. The
device meets the requirements of EIA/TIA and
V.28/V.24 communication standards providing
high data rate capability and enhanced
electrostatic discharge (ESD) protection. All
transmitter outputs and receiver inputs are
protected to ±8 kV using IEC 1000-4-2 contact
discharge and ±15 kV using the human body
model. The receiver R2 is always active to
implement a wake-up feature for serial port.
ST3241EB
ST3241EC
SSOP-28
It is a complete serial port (3 drivers, 5 receivers)
intended for notebook or sub-notebook
computers. Receivers R1 and R2 have extra
outputs in addition to their standard outputs.
These extra outputs are always active.
Typical applications are in notebooks, subnotebooks, palmtop computers, battery-powered
equipment, hand-held equipment, peripherals and
printers.
The ST3241E has a proprietary low-dropout
transmitter output stage enabling true RS-232
performance from a 3.0 V to 5.5 V supply with a
dual charge pump. The device is guaranteed to
run at data rates of 250 kbps while maintaining
RS-232 output levels.
Table 1. Device summary
Order code Temperature range Package Packaging
ST3241ECPR 0 to 70°C SSOP-28 (tape and reel) 1350 parts per reel
ST3241EBPR –40 to 85°C SSOP-28 (tape and reel) 1350 parts per reel
September 2010 Doc ID 9066 Rev 5 1/13
www.st.com
1
Contents ST3241EB - ST3241EC
Contents
1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2/13 Doc ID 9066 Rev 5
ST3241EB - ST3241EC Pin configuration
1 Pin configuration
Figure 1. Pin configuration
Table 2. Pin description
Pin
number
1C
2C
3 V- –5.5 V generated by the charge pump
4R1
5R2
6R3
7R4
8R5
9T1
10 T2
11 T3
12 T3
13 T2
14 T1
15 R5
16 R4
Symbol Name and function
+ Positive terminal of inverting charge pump capacitor
2
Negative terminal of inverting charge pump capacitor
2
First receiver input voltage
IN
Second receiver input voltage
IN
Third receiver input voltage
IN
Fourth receiver input voltage
IN
Fifth receiver input voltage
IN
OUT
OUT
OUT
OUT
OUT
First transmitter output voltage
Second transmitter output voltage
Third transmitter output voltage
Third transmitter input voltage
IN
Second transmitter input voltage
IN
First transmitter input voltage
IN
Fifth receiver output voltage
Fourth receiver output voltage
CS10800
Doc ID 9066 Rev 5 3/13
Pin configuration ST3241EB - ST3241EC
Table 2. Pin description (continued)
Pin
number
17 R3
18 R2
19 R1
20 R2
21 R1
Symbol Name and function
OUT
OUT
OUT
OUTB
OUTB
Third receiver output voltage
Second receiver output voltage
First receiver output voltage
Non-inverting complementary receiver output, always active for wake-up
Non-inverting complementary receiver output, always active for wake-up
22 SHDN Shutdown control. Active low.
23 EN Receiver enable. Active low
24 C
- Negative terminal of voltage - charge pump capacitor
1
25 GND Ground
26 V
CC
Supply voltage
27 V+ 5.5 V Generated by the charge pump
28 C1+ Positive terminal of voltage - charge pump capacitor
Table 3. Shutdown and enable control truth table
SHDN EN T
0 0 HIGH Z ACTIVE ACTIVE
OUT
R
OUT
R
OUTB
0 1 HIGH Z HIGH Z ACTIVE
1 0 ACTIVE ACTIVE ACTIVE
1 1 ACTIVE HIGH Z ACTIVE
4/13 Doc ID 9066 Rev 5