DATASHEET
ISL33334E, ISL33337E
3.3V, ±15kV ESD Protected, Two Port, Dual Protocol (RS-232/RS-485)
Transceivers
The
ISL33334E, ISL33337E
are two port interface ICs where
port 1 is configured as a dual (2 Tx, 2 Rx) RS-232 transceiver
and port 2 is a single RS-485/RS-422 transceiver.
The on-board charge pump generates RS-232 compliant ±5V
Tx output levels from a single V
CC
supply as low as 3.15V. The
transceivers are RS-232 compliant, with the Rx inputs
handling up to ±25V.
The port 2 transceiver supports both the RS-485 and RS-422
differential communication standards. The receiver features
“full fail-safe” operation, so the Rx output remains in a high
state if the inputs are open or shorted together. The
transmitter supports two data rates, one of which is slew rate
limited for problem free communication at low data rates. The
active low Rx enable pin (RE485) allows Tx/Rx direction
control, via a single signal, simply by connecting the
corresponding DE485 and RE485 pins together.
The ISL33334E and ISL33337E also include a shutdown
function, which disables the Tx and Rx outputs, disables the
charge pumps and places the IC in a low current (40µA) mode.
The ISL33337E is a QFN packaged device for space
constrained applications.
FN8776
Rev 1.00
October 21, 2016
Features
• ±15kV (HBM) ESD protected bus pins (RS-232 or RS-485)
• Operates from a single 3.3V supply
• Two independent ports, port 1 set for RS-232 (2 Transceivers)
and port 2 for RS-485/RS-422 (1 transceiver)
• True flow-through pinouts (Rx inputs and Tx outputs all on
the same side) simplify board layouts
• Pb-free (RoHS compliant)
• Full fail-safe (open/short) RS-485/422 Port 2 Rx
• User selectable RS-485 data rates
- Fast speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . up to 20Mbps
- Slew rate limited . . . . . . . . . . . . . . . . . . . . . . up to 115kbps
• Fast RS-232 data rate . . . . . . . . . . . . . . . . . . . . up to 400kbps
• Small charge pump capacitors . . . . . . . . . . . . . . . . 4 x 0.1µF
• Low current shutdown mode . . . . . . . . . . . . . . . . . . . . . . 40µA
• QFN package saves board space (ISL33337E only)
Applications
• Gaming applications (e.g., slot machines)
• Single board computers
• Factory automation
• Security networks
• Industrial/process control networks
• Level translators (e.g., RS-232 to RS-422)
• Point-of-sale equipment
Related Literature
• For a full list of related documents, visit our website
-
ISL33334E, ISL33337E
product pages
TABLE 1. SUMMARY OF FEATURES
PART NUMBER
ISL33334E
ISL33337E
PACKAGE OPTION
28 Ld SSOP
40 Ld QFN (6x6mm)
PORT 2
RS-485 DATA RATE (bps)
20M, 115k
20M, 115k
PORT 1
RS-232 DATA RATE (bps)
400k
400k
LOW POWER
SHUTDOWN?
YES
YES
PORT 2
RS-485 Rx AND Tx ENABLE?
YES
YES
FN8776 Rev 1.00
October 21, 2016
Page 1 of 23
ISL33334E, ISL33337E
Ordering Information
PART NUMBER
(Notes
2, 3)
ISL33334EIAZ
ISL33334EIAZ-T (Notes
1)
ISL33337EIRZ
ISL33337EIRZ-T (Notes
1)
PART MARKING
33334E IAZ
33334E IAZ
33337E IRZ
33337E IRZ
TEMP. RANGE
(°C)
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
TAPE AND REEL
(UNITS)
-
1k
-
1k
250
PACKAGE
(RoHS COMPLIANT)
28 Ld SSOP
28 Ld SSOP
40 Ld QFN
40 Ld QFN
40 Ld QFN
PKG.
DWG. #
M28.209
M28.209
L40.6x6
L40.6x6
L40.6x6
ISL33337EIRZ-T7A (Notes
1)
33337E IRZ
NOTES:
1. Refer to
TB347
for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials and 100% matte tin
plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil
Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), see product information page for
ISL33334E, ISL33337E.
For more information on MSL, see tech brief
TB363.
TABLE 2. KEY DIFFERENCES BETWEEN FAMILY OF PARTS
PART NUMBER
ISL33354E
ISL33357E
ISL33334E
ISL33337E
VCC
(V)
5
5
3.3
3.3
PKG
28Ld SSOP
40Ld QFN
28Ld SSOP
40Ld QFN
RS485 (bps)
DATA RATE
20M, 115k
20M, 115k
20M, 115k
20M, 115k
RS232 (bps)
DATA RATE
650k
650k
400k
400k
NOTE: For a full list of dual protocol transceivers, please visit our
website.
Pin Configurations
ISL33334E
(28 LD SSOP)
TOP VIEW
C1-
NC
NC
C1+ 1
C1- 2
V+ 3
R1IN 4
R2IN 5
T1OUT 6
T2OUT 7
*GND 8
*V
CC
9
Y 10
Z 11
A 12
B 13
SLOW485 14
D
R
D
D
R
R
PORT 1
28 C2+
27 C2-
26 V
CC
25 R2OUT
24 R1OUT
23 T2IN
22 T1IN
21 SHDN
20 DI
19 DE485
18 RO
17 V-
16 RE485
PORT 2
15 GND
V+
R1IN
R2IN
T1OUT
T2OUT
*GND
*V
CC
Y
Z
A
* NOT A SUPPLY PIN, BUT MUST BE CONNECTED TO THE
NOTED SUPPLY.
1
2
3
4
5
6
7
8
9
ISL33337E
(40 LD QFN)
TOP VIEW
V
CC
NC
NC
32
V
CC
31
30 R2OUT
R
D
D
29 R1OUT
28 T2IN
27 T1IN
26 *V
CC
25 SHDN
PORT 2
D
24 DI
23 DE485
22 RO
EP
16
GND
17
*GND
18
RE485
19
20
*V
CC
21 DNC
C1+
C2+
36
C2-
35
R
40
39
38
37
34
33
PORT 1
R
10
11
12
*V
CC
13
SLOW485
14
*V
CC
15
GND
FN8776 Rev 1.00
October 21, 2016
V-
B
Page 2 of 23
ISL33334E, ISL33337E
Pin Descriptions
PIN # for
PIN NAME SSOP
NC
DNC
SHDN
V
CC
GND
*V
CC
*GND
RxIN
RxOUT
TxIN
TxOUT
C1+
C1-
C2+
C2-
V+
V-
A
B
Y
Z
DI
RO
SLOW485
RE485
DE485
EP
-
-
21
26
15
9
8
4, 5
24, 25
22, 23
6, 7
1
2
28
27
3
17
12
13
10
11
20
18
14
16
19
-
PIN # for
QFN
PORT/
MODE
No Internal Connection.
Do not make any external connections to this pin.
A low on SHDN disables the charge pumps, disables all the outputs and places the device in low power
shutdown. Internally pulled-high. SHDN = 1 for normal operation.
System power supply input (3.15V to 3.45V). Both pins 31 and 34 must connect to the V
CC
supply.
Ground connection. QFN pins 15 and 16 must both connect to GND. This is also the potential of the QFN’s
exposed metal pad (EP).
For proper operation, connect this lead to the V
CC
supply. This is not a power supply lead, so no decoupling
is required.
For proper operation, connect this lead to GND. This is not a power supply lead.
FUNCTION
32, 33, 39, BOTH
40
21
25
31, 34
15, 16
BOTH
BOTH
BOTH
BOTH
12, 20, 7, BOTH
14, 26
6, 17
2, 3
29, 30
27, 28
4, 5
37
38
36
35
1
19
10
11
8
9
24
22
13
18
23
EP
BOTH
1 / RS-232 RS-232 receiver input with ±15kV ESD protection. A low on RxIN forces RxOUT high; a high on RXIN forces
RxOUT low.
1 / RS-232 RS-232 receiver output.
1 / RS-232 RS-232 transmitter input. A low on TxIN drives the corresponding TxOUT high, while a high on TxIN drives
the corresponding TxOUT low.
1 / RS-232 RS-232 transmitter output with ±15kV ESD protection.
1 / RS-232 External charge pump capacitor is connected to this lead.
1 / RS-232 External charge pump capacitor is connected to this lead.
1 / RS-232 External charge pump capacitor is connected to this lead.
1 / RS-232 External charge pump capacitor is connected to this lead.
1 / RS-232 Internally generated positive RS-232 transmitter supply (+5.5V).
1 / RS-232 Internally generated negative RS-232 transmitter supply (-5.5V).
2 / RS-485 RS-485 noninverting receiver input with ±15kV ESD protection.
2 / RS-485 RS-485 inverting receiver input with ±15kV ESD protection.
2/ RS-485 RS-485 noninverting driver output with ±15kV ESD protection.
2/ RS-485 RS-485 inverting driver output with ±15kV ESD protection.
2 / RS-485 RS-485 driver input. A low on DI forces output Y low and output Z high.
2 / RS-485 RS-485 receiver output: If A > B by at least -40mV, RO is high; If A < B by -200mV or more, RO is low;
RO = High if A and B are unconnected (floating) or shorted together (i.e., full fail-safe).
2 / RS-485 RS-485 data rate control. A low on SLOW485 selects the 115kbps RS-485 data rate (slew rate limited
output transitions); a high selects the 20Mbps data rate (full speed transitions). Internally pulled-high.
2/ RS-485 RS-485 active low receiver output enable. RO is enabled when RE485 is low; RO is high impedance when
RE485 is high. Internally pulled low.
2/ RS-485 RS-485 driver output enable (DE). The driver outputs, Y and Z, are enabled by driving DE485 high. They
are high impedance when DE485 is low. Internally pulled high.
BOTH
QFN exposed thermal pad (EPAD). Connect to GND.
TABLE 3. ISL33334E AND ISL33337E FUNCTION TABLE
INPUTS
RECEIVER OUTPUTS
R1OUT
AND
R2OUT
ON
DRIVER OUTPUTS
T1OUT AND
T2OUT
ON
CHARGE
PUMPS
(Note
4)
ON
PORT
1
SHDN
1
RE485
N.A.
DE485
N.A.
SLOW485
N.A.
RO
N.A.
Y AND Z
N.A.
DRIVER
DATA
RATE
(bps)
400k
MODE
RS-232
FN8776 Rev 1.00
October 21, 2016
Page 3 of 23
ISL33334E, ISL33337E
TABLE 3. ISL33334E AND ISL33337E FUNCTION TABLE
INPUTS
RECEIVER OUTPUTS
R1OUT
AND
R2OUT
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
High-Z
DRIVER OUTPUTS
T1OUT AND
T2OUT
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
High-Z
CHARGE
PUMPS
(Note
4)
ON
ON
ON
ON
ON
ON
OFF
DRIVER
DATA
RATE
(bps)
115k
115k
115k
20M
20M
20M
N.A.
PORT
2
2
2
2
2
2
1 AND 2
SHDN
1
1
1
1
1
1
0
RE485
0
0
1
0
0
1
X
DE485
0
1
1
0
1
1
X
SLOW485
0
0
0
1
1
1
X
RO
ON
ON
High-Z
ON
ON
High-Z
High-Z
Y AND Z
High-Z
ON
ON
High-Z
ON
ON
High-Z
MODE
RS-485 Rx
RS-485 Tx
and Rx
RS-485 Tx
RS-485 Rx
RS-485 Tx
and Rx
RS-485 Tx
Shutdown
NOTE:
4. Charge pumps are off if SHDN = 0. If SHDN = 1, the charge pumps are on.
Truth Tables
RS-232 TRANSMITTING (PORT 1)
INPUTS
SHDN
1
1
1
1
0
T1IN
0
0
1
1
X
T2IN
0
1
0
1
X
OUTPUTS
T1OUT
1
1
0
0
High-Z
T2OUT
1
0
1
0
High-Z
SHDN
1
1
1
1
1
0
RS-232 RECEIVING (PORT 1)
INPUTS
SHDN
1
1
1
1
1
0
R1IN
0
0
1
1
Open
X
R2IN
0
1
0
1
Open
X
OUTPUTS
R1OUT
1
1
0
0
1
High-Z
R2OUT
1
0
1
0
1
High-Z
SHDN
1
1
1
1
0
RS-485 TRANSMITTING (PORT 2)
INPUTS
DE485
1
1
1
1
0
X
DI
0
1
0
1
X
X
SLOW485
0
0
1
1
X
X
Y
0
1
0
1
OUTPUTS
Z
1
0
1
0
DATA RATE
(bps)
115k
115k
20M
20M
N.A.
N.A.
High-Z High-Z
High-Z High-Z
RS-485 RECEIVING (PORT 2)
INPUTS
RE485
0
0
0
1
X
A-B
≥-40mV
≤-200mV
Open or Shorted together
X
X
OUTPUT
RO
1
0
1
High-Z
High-Z
FN8776 Rev 1.00
October 21, 2016
Page 4 of 23
ISL33334E, ISL33337E
Typical Operating Circuits
+3.3V
+
0.1µF
1
2
C1+
C1-
C2+
C2-
V- 17
9, 26
V
CC
V+
3
+ C
3
0.1µF
C
4
0.1µF
+
R1OUT
C
1
0.1µF
C
2
0.1µF
+
28
+
27
R1IN
4
5k?
5
5k?
7
6
R
24
R2IN
R
25
R2OUT
T2OUT
T1OUT
D
D
23
22
T2IN
T1IN
B
A
13
12
R
18
16
RE485
RO
Z
Y
11
10
D
20
19
DE485
21
14
GND
8, 15
SHDN
DI
V
CC
V
CC
SLOW485
NOTE: PINOUT FOR SSOP
FIGURE 1. PORT RS-232 MODE AND 1 PORT RS-485 MODE
FN8776 Rev 1.00
October 21, 2016
Page 5 of 23