rev. 4/12/01

SP6661 Evaluation Board Manual

© Copyright 2001 Sipex Corporation

2

BOARD LAYOUT

The SP6661 Evaluation Board has been

designed to easily and conveniently provide

access to all Inputs and Outputs of the

SP6661 device under test.

Position the

board with the silkscreen lettering upright

(also see the drawing on the front page of

this manual) and you will see two circuits –

the Doubler Circuit on top, and the Inverter

Circuit below. Also, note the Doubler Circuit

is followed by an LDO Circuit, producing a

5V regulated output from a 3V input to the

Doubler. The Input and Output connections

are made with raised female pin receptacles

which can accommodate easy-hook con-

nection leads for power and meter connec-

tions, as well as scope probe hooks and

grounds for waveform measurements.

USING THE EVALUATION BOARD

Connect the SP6661 Evaluation Board

Doubler Circuit or Inverter Circuit to a posi-

to not switch power on until power connec-

tions are made to the evaluation board.

Evaluating Doubler Circuit

GND — U1-5 — Connect to external supply

GND.

CAP+ — U1-2 — Use to monitor Charge

Pump Frequency (1/2 OSC pin frequency).

GND — U1-5 — Connect to Load, Meter or

Scope GND.

FC — U1-1 — Connect to OPEN for Low

SP6661 EVALUATION BOARD

Evaluating Doubler Circuit with 5V LDO

Regulator

Same connections as Doubler above, but

with additional LDO outputs:

+5 — U2-5 — Connect to Load, Meter or

GND — U2-2 — Connect to Load, Meter or

Scope GND.

Evaluating Inverter Circuit

GND — U3-3 — Connect to external supply

GND.

CAP+ — U3-2 — Use to monitor Charge

Pump Frequency (1/2 OSC pin frequency).

GND — U3-3 — Connect to Load, Meter or

Scope GND.

FC — U3-1 — Connect to OPEN for Low

Evaluating Oscillator Performance with

Inverter or Doubler Circuit

To accurately measure the internal oscilla-

tor frequency at pin 7 is extremely difficult,

since any connection to this pin may induce

capacitance which will change the frequency

(1/RoscCosc). It is for this reason that the

SP6661 Evaluation Board has only a small

pad connection to it and not a pin receptacle.

Alternatively, you can measure the charge

pump frequency at the CAP+ pin, which

equals _ the OSC pin frequency.

To run the Inverter or Doubler Circuit at other

frequencies, the OSC pin can be driven with

an external oscillator with a square wave of

cally the circuits can perform up to oscillator

frequencies of 900kHz.