SP6661EB Datasheet, PDF (2/5 Pages) Sipex Corporation – Evaluation Board Manual

SP6661 EVALUATION BOARD
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-
tive power supply for V_IN. It is good practice
to not switch power on until power connec-
tions are made to the 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
Scope. V_OUT = +5.0V.
GND — U2-2 — Connect to Load, Meter or
Scope GND.
Evaluating Inverter Circuit
V_IN — U3-8 — Connect to external supply
V_IN = +1.5 to +5.0V.
GND — U3-3 — Connect to external supply
GND.
CAP+ — U3-2 — Use to monitor Charge
Pump Frequency (1/2 OSC pin frequency).
V_OUT — U3-5 — Connect to Load, Meter or
Scope. V_OUT = -1.5 to –5.0V.
GND — U3-3 — Connect to Load, Meter or
Scope GND.
FC — U3-1 — Connect to OPEN for Low
Frequency, to V_OUT for High Frequency.
Evaluating Doubler Circuit
V_IN — U1-3 — Connect to external supply
V_IN = +2.5 to +5.0V.
GND — U1-5 — Connect to external supply
GND.
CAP+ — U1-2 — Use to monitor Charge
Pump Frequency (1/2 OSC pin frequency).
V_OUT — U1-8 — Connect to Load, Meter or
Scope. V_OUT = +5.0 to +10.0V.
GND — U1-5 — Connect to Load, Meter or
Scope GND.
FC — U1-1 — Connect to OPEN for Low
Frequency, to V_OUT for High Frequency.
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
0 to V_IN volts. Tests have shown that typi-
cally the circuits can perform up to oscillator
frequencies of 900kHz.
rev. 4/12/01
SP6661 Evaluation Board Manual
2
© Copyright 2001 Sipex Corporation