ISL33334E Datasheet, PDF (3/23 Pages) Intersil Corporation – Operates from a single 3.3V supply

ISL33334E, ISL33337E
Pin Descriptions
PIN # for PIN # for
PIN NAME SSOP
QFN
PORT/
MODE
FUNCTION
NC
- 32, 33, 39, BOTH
No Internal Connection.
40
DNC
-
21 BOTH
Do not make any external connections to this pin.
SHDN
21
25 BOTH
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.
V_CC
26
31, 34 BOTH
System power supply input (3.15V to 3.45V). Both pins 31 and 34 must connect to the V_CC supply.
GND
15
15, 16 BOTH
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).
*V_CC
9 12, 20, 7, BOTH
14, 26
For proper operation, connect this lead to the V_CC supply. This is not a power supply lead, so no decoupling
is required.
*GND
8
6, 17 BOTH
For proper operation, connect this lead to GND. This is not a power supply lead.
RxIN
4, 5
2, 3 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.
RxOUT 24, 25 29, 30 1 / RS-232 RS-232 receiver output.
TxIN 22, 23 27, 28 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.
TxOUT 6, 7
4, 5 1 / RS-232 RS-232 transmitter output with ±15kV ESD protection.
C1+
1
37 1 / RS-232 External charge pump capacitor is connected to this lead.
C1-
2
38 1 / RS-232 External charge pump capacitor is connected to this lead.
C2+
28
36 1 / RS-232 External charge pump capacitor is connected to this lead.
C2-
27
35 1 / RS-232 External charge pump capacitor is connected to this lead.
V+
3
1 1 / RS-232 Internally generated positive RS-232 transmitter supply (+5.5V).
V-
17
19 1 / RS-232 Internally generated negative RS-232 transmitter supply (-5.5V).
A
12
10 2 / RS-485 RS-485 noninverting receiver input with ±15kV ESD protection.
B
13
11 2 / RS-485 RS-485 inverting receiver input with ±15kV ESD protection.
Y
10
8 2/ RS-485 RS-485 noninverting driver output with ±15kV ESD protection.
Z
11
9 2/ RS-485 RS-485 inverting driver output with ±15kV ESD protection.
DI
20
24 2 / RS-485 RS-485 driver input. A low on DI forces output Y low and output Z high.
RO
18
22 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).
SLOW485 14
13 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.
RE485 16
18 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.
DE485 19
23 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.
EP
-
EP BOTH
QFN exposed thermal pad (EPAD). Connect to GND.
PORT
1
SHDN
1
INPUTS
RE485
N.A.
DE485
N.A.
TABLE 3. ISL33334E AND ISL33337E FUNCTION TABLE
RECEIVER OUTPUTS
DRIVER OUTPUTS
SLOW485 RO
R1OUT
AND
R2OUT
Y AND Z
T1OUT AND
T2OUT
N.A.
N.A.
ON
N.A.
ON
CHARGE
PUMPS
(Note 4)
ON
DRIVER
DATA
RATE
(bps)
MODE
400k RS-232
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FN8776.1
October 21, 2016