ISL4270E Datasheet, PDF (2/13 Pages) Intersil Corporation – QFN Packaged, ±15kV ESD Protected, +3V to +5.5V, 300nA, 250kbps, RS-232 Transceivers with Enhanced Automatic Powerdown and a Separate Logic Supply

Pinout
ISL4270E
ISL4270E (QFN)
TOP VIEW
32 31 30 29 28 27 26 25
NC ₁
C2+ ₂
C2- ₃
V- ₄
T1_{IN 5}
T2_{IN 6}
INVALID ₇
24 NC
23 ^T1OUT
22 ^T2OUT
21 ^T3OUT
PD
20 ^R1IN
19 ^R2IN
18 ^R3IN
NC ₈
17 ^NC
9 10 11 12 13 14 15 16
Pin Descriptions
PIN
V_CC
V+
V-
GND
C1+
C1-
C2+
C2-
FUNCTION
System power supply input (3.0V to 5.5V).
Internally generated positive transmitter supply (+5.5V).
Internally generated negative transmitter supply (-5.5V).
Ground connection. This is also the potential of the thermal pad (PD).
External capacitor (voltage doubler) is connected to this lead.
External capacitor (voltage doubler) is connected to this lead.
External capacitor (voltage inverter) is connected to this lead.
External capacitor (voltage inverter) is connected to this lead.
T_IN
TTL/CMOS compatible transmitter Inputs. The switching point is a function of the V_L voltage.
T_OUT ±15kV ESD Protected, RS-232 level (nominally ±5.5V) transmitter outputs.
R_IN
±15kV ESD Protected, RS-232 compatible receiver inputs.
R_OUT TTL/CMOS level receiver outputs. Swings between GND and V_L.
V_L
Logic-Level Supply. All TTL/CMOS inputs and outputs are powered by this supply.
INVALID Active low output that indicates if no valid RS-232 levels are present on any receiver input. Swings between GND and V_L.
FORCEOFF Active low to shut down transmitters and on-chip power supply. This overrides any automatic circuitry and FORCEON (see Table 2).
The switching point is a function of the V_L voltage.
FORCEON Active high input to override automatic powerdown circuitry thereby keeping transmitters active (FORCEOFF must be high). The
switching point is a function of the V_L voltage.
PD
Exposed Thermal Pad. Connect to GND.
2
FN6041.2
June 16, 2010