SP3508CF datasheet(26/33 Pages) SIPEX

部件名	SP3508CF

功能描述	Rugged 3.3V, 20Mbps, 8 Channel Multiprotocol Transceiver with Programmable DCE/DTE and Termination Resistors

PDF	33 Pages

Scroll/Zoom	100%

制造商	SIPEX [Sipex Corporation]

网页	http://www.sipex.com

标志

26 / 33 page

Date: 06/14/04

SP3508 Enhanced WAN Multi–Mode Serial Transceiver

VCC = +3V

+6V

VSS1 Storage Capacitor

VDD Storage Capacitor

–

CVDD

CVSS1

Figure 48. Charge Pump - Phase 4.

2-phased inverter pump

Phase 1

Please refer to figure below: In the first phase of the clock cycle, switches S2 and S4 are opened and S1 and

S3 closed. This connects the flying capacitor, C3, from Vin to ground. C3 charge up to the input voltage

applied at Vcc.

Phase 2

In the second phase of the clock cycle, switches S2 and S4 are closed and S1 and S3 are opened. This

connects the flying capacitor, C3, in parallel with the output capacitor, CVSS2. The Charge stored in C3 is

now transferred to CVSS2. Simultaneously, the negative side of CVSS2 is connected to VSS2 and the positive

side is connected to ground. With the voltage across CVSS2 smaller than the voltage across C3, the charge

flows from C3 to CVSS2 until the voltage at the VSS2 equals -VCC.

VSS2

CVSS2

VCC

VSS2 = -VCC

Figure 49. Circuit for an Ideal Voltage Inverter.

FEATURES

SP3508CF 数据表(PDF) 26 Page - Sipex Corporation