SP385ECT-L Datasheet, PDF (9/15 Pages) Exar Corporation – Enhanced +3V or +5V RS-232 Line Driver/Receiver

V_CC = +5V
+
C_{1 –}
–5V
+5V
+
C_{2 –}
–5V
Figure 2. Charge Pump — Phase 1
V_CC = +5V
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
+
C_{1 –}
Figure 3. Charge Pump — Phase 2
V_CC = +5V
+
C_{2 –}
-10V
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
+
C_{1 –}
–5V
+5V
+
C_{2 –}
–5V
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 4. Charge Pump — Phase 3
V_CC = +5V
+
C_{1 –}
+10V
+
C_{2 –}
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 5. Charge Pump — Phase 4
Shutdown (ON/OFF)
The SP385E has a shut-down/standby mode
to conserve power in battery-powered systems.
To activate the shutdown mode, which stops
the operation of the charge pump, a logic "0" is
applied to the appropriate control line. The shut-
down mode is controlled on the SP385E by a
logic "0" on the ON/OFF control line (pin 18 for
the SOIC and pin 20 for the SSOP packages);
this puts the transmitter outputs in a tri-state
mode.
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com

SP385E_100_030811