SP504MCM View Datasheet(PDF) - Exar Corporation
Part Name
Description
Manufacturer
SP504MCM Datasheet PDF : 32 Pages
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VCC = +5V
+
C1 –
+
C2 –
C4
+ – VDD Storage Capacitor
–10V
– + VSS Storage Capacitor
C3
Figure 15a. Charge Pump Phase 2 for ±10V.
VCC = +5V
+
C1 –
–5V
+5V
+
C2 –
–5V
C4
+ – VDD Storage Capacitor
– + VSS Storage Capacitor
C3
Figure 16. Charge Pump Phase 3.
Phase 2 (±10V)
— VSS transfer — Phase two of the clock
connects the negative terminal of C2 to
the VSS storage capacitor and the positive
terminal of C2 to ground, and transfers the
generated –l0V or the generated –5V to C3.
Simultaneously, the positive side of capacitor
C 1 is switched to +5V and the negative side
is connected to ground.
Phase 2 (±5V)
— VSS & VDD charge storage — C1+ is recon-
nected to VCC to recharge the C1 capacitor.
C2+ is switched to ground and C2– is connected
to C3. The 5V charge from Phase 1 is now
VCC = +5V
+
C1 –
+
C2 –
C4
+ – VDD Storage Capacitor
–5V
– + VSS Storage Capacitor
C3
Figure 15b. Charge Pump Phase 2 for ±5V.
VCC = +5V
+
C1 –
+10V
+
C2 –
C4
+ – VDD Storage Capacitor
– + VSS Storage Capacitor
C3
Figure 17. Charge Pump Phase 4.
transferred to the VSS storage capacitor. VSS
receives a continuous charge from either C1
or C2. With the C1 capacitor charged to 5V,
the cycle begins again.
Phase 3
— VDD charge storage — The third phase
of the clock is identical to the first phase
— the charge transferred in C1 produces
–5V in the negative terminal of C1, which
is applied to the negative side of capacitor
C2. Since C2+ is at +5V, the voltage potential
across C2 is l0V. For the 5V output, C2+ is
connected to ground so that the potential
on C2 is only +5V.
+10V
C2+
(a)
GND
GND
C2–
(b)
–10V
+5V
C2+
GND
GND
C2–
–5V
Figure 18a and 18b. Charge Pump Waveforms
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
15
SP504_102_121708
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