±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
Pin Description
MAX3222E
MAX3232E
SO/DIP
TSSOP/ SO/DIP/
SSOP SSOP
TSSOP
PIN
MAX3241E
MAX3237E SSOP/SO QFN
MAX3246E
NAME
FUNCTION
1
1
—
—
13*
2
2
1
2
28
23
22
B3
28
28
F3
EN
Receiver Enable. Active low.
Positive Terminal of Voltage-
C1+ Doubler Charge-Pump
Capacitor
3
3
2
3
27
27
27
F1
V+
+5.5V Generated by the
Charge Pump
Negative Terminal of Voltage-
4
4
3
4
25
24
23
F4
C1- Doubler Charge-Pump
Capacitor
5
5
4
5
1
1
29
E1
C2+ Positive Terminal of Inverting
Charge-Pump Capacitor
6
6
5
6
3
2
30
D1
C2-
Negative Terminal of Inverting
Charge-Pump Capacitor
7
7
6
7
4
3
31
C1
V-
-5.5V Generated by the
Charge Pump
8, 15 8, 17 7, 14 8, 17
5, 6, 7,
10, 12
9, 10,
11
6, 7,
8
F6, E6, D6
T_OUT
RS-232 Transmitter Outputs
9, 14 9, 16 8, 13 9, 16 8, 9, 11
4–8
1–5
A4, A5,
A6, B6, C6
R_IN
RS-232 Receiver Inputs
10, 13 10, 15 9, 12 12, 15
11, 12 12, 13 10, 11 13, 14
16
18
15
18
17
19
16
19
18
20
—
—
18, 20,
21
17*, 19*,
22*, 23*,
24*
2
26
14*
15–19
13, 14,
15, 17,
18
C2, B1,
A1, A2, A3
12, 13,
14
10, 11, E3, E2, D2
12
25
24
F5
26
26
F2
22
21
B2
R_OUT
T_IN
GND
VCC
SHDN
TTL/CMOS Receiver Outputs
TTL/CMOS Transmitter Inputs
Ground
+3.0V to +5.5V Supply Voltage
Shutdown Control. Active low.
—
11, 14
—
1, 10, 11,
20
—
C3, D3, B4,
No Connection. For
—
9, 16, C4, D4, E4,
25, 32 B5, C5, D5,
N.C.
MAX3246E, these locations
are not populated with solder
E5
bumps.
—
—
—
—
15*
—
—
MegaBaud Control Input.
—
MBAUD Connect to GND for normal
operation; connect to VCC for
1Mbps transmission rates.
—
—
—
—
Noninverting Complementary
16
20, 21 19, 20
—
R_OUTB Receiver Outputs. Always
active.
*These pins have an active positive feedback resistor internal to the MAX3237E, allowing unused inputs to be left unconnected.
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