7
LT 1331
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
ESD PROTECTIO
U
ESD Test Circuit
The RS232 line inputs of the LT1331 have on-chip protec-
tion from ESD transients up to ±10kV. The protection
structures act to divert the static discharge safely to
system ground. In order for the ESD protection to function
effectively, the power supply and ground pins of the
LT1331 must be connected to ground through low imped-
ances. The power supply decoupling capacitors and charge
pump storage capacitors provide this low impedance in
normal application of the circuit. The only constraint is that
low ESR capacitors must be used for bypassing and
charge storage. ESD testing must be done with pins V
CC
,
V
L
, V
+
, V
–
and GND shorted to ground or connected with
low ESR capacitors.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
DRIVER 1 IN
RX1 OUT
DRIVER 2 IN
RX2 OUT
RX3 OUT
RX4 OUT
DRIVER 3 IN
RX5 OUT (LOW-Q)
V
+
0.1µF
0.2µF
0.2µF
0.1µF
GND
DRIVER DISABLE
NC
RS232
LINE PINS
PROTECTED
TO ±10kV
V
–
LT1331
DRIVER 1 OUT
RX1 IN
DRIVER 2 OUT
RX2 IN
RX3 IN
RX4 IN
DRIVER 3 OUT
RX5 IN (LOW-Q)
ON/OFF
0.1µF
1331 ESD TC
0.1µF
3.3V
+
+
+
+
+
+
5V V
CC
PACKAGE DESCRIPTIO
U
Dimensions in inches (millimeters) unless otherwise noted.
N28 1197
0.009 – 0.015
(0.229 – 0.381)
0.625
+0.035
–0.015
+0.889
–0.381
15.87
()
0.600 – 0.625
(15.240 – 15.875)
0.505 – 0.560*
(12.827 – 14.224)
1.455*
(36.957)
MAX
12
3
4
5
6
7
8
9
10
27
19
20212224
23
252628
11 12 13 14
15
16
1718
0.070
(1.778)
TYP
0.015
(0.381)
MIN
0.125
(3.175)
MIN
0.150 ± 0.005
(3.810 ± 0.127)
0.018 ± 0.003
(0.457 ± 0.076)
0.035 – 0.080
(0.889 – 2.032)
0.100 ± 0.010
(2.540 ± 0.254)
0.045 – 0.065
(1.143 – 1.651)
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
NW Package
28-Lead PDIP (Wide 0.600)
(LTC DWG # 05-08-1520)
G Package
28-Lead Plastic SSOP (0.209)
(LTC DWG # 05-08-1640)
G28 SSOP 0694
0.301 – 0.311
(7.65 – 7.90)
1234
5
6
7
8 9 10 11 12 1413
0.397 – 0.407*
(10.07 – 10.33)
2526 22 21 20 19 18
17
16 1523242728
0.068 – 0.078
(1.73 – 1.99)
0.002 – 0.008
(0.05 – 0.21)
0.0256
(0.65)
BSC
0.010 – 0.015
(0.25 – 0.38)
0.005 – 0.009
(0.13 – 0.22)
0° – 8°
0.022 – 0.037
(0.55 – 0.95)
0.205 – 0.212**
(5.20 – 5.38)
DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
DIMENSIONS DO NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
*
**
