KEPCO BOP 20-20DC Modification Sheet

MODIFICATION OF STANDARD

KEPCO®

KEPCO MODEL BOP 20-20MC
KEPCO MODEL BOP 20-20DC

THE POWER SUPPLIER™

The Kepco Models BOP 20-20MC and BOP 20-20DC have been modified from standard Kepco
Models BOP 20-20M and BOP 20-20D, respectively, to be stable handling capacitive loads up
to 10 mF.

INSTRUCTION MANUAL CORRECTIONS:

This modification makes the BOP more suitable for a wide variety of applications such as
solar cell/ solar panel testing, piezoelectric device driving/ testing, capacitor testing, capacitive
transducer driving/testing and powering industrial or lab-type applications for capacitive or
capacitive-resistive loads.

Static specifications representing the unit’s accuracy in Voltage mode are identical to the
standard BOP models, while the ripple and noise specifications are better (approximately 50%
lower) for MC and DC models than standard BOP models.

Specifications listed in Table 1 are for BOP 20-20MC and BOP 20-20DC in Voltage Mode.

TABLE 1. BOP 20-20MC AND BOP 20-20DC SPECIFICATIONS

Bandwidth (DC to f-3dB)

Resistive Load, Nominal

4.8 KHz 5.3 KHz 75 µS 225 µS

NOTES:
(1) Bandwidth for this model with resistive load is larger than for standard BOP with resistive load.
(2) Nonuniformities of the frequency response for the standard 10µF load create a larger 3-dB bandwidth than

for the resistive load.
(3) 10% to 90%, with nominal resistive load.
(4) Load between infinity and nominal resistive load values.

(1)

Capacitive Load, 10µF

(2)

Rise/Fall Time

(3)

Recovery at Step Load

(4)

In voltage mode the bandwidth of the BOP 20-20MC and DC models is higher than the stan­dard BOP. Nonuniformities of the frequency response can be nearly eliminated by reducing the
bandwidth in Voltage mode. Bandwidth can be reduced in a predictable manner by increasing
the internal compensation capacitance by placing an external capacitor in parallel with C21 of
Assembly A1 (see Table 2 and Figure 1).

TABLE 2. BANDWIDTH CORRECTION

EXTERNAL CAPACITOR

(ACROSS A1C21, SEE FIGURE 1)

1 nF 2.2 nF 4.7 nF 15 nF 33 nF 47 nF 100 nF

CORRECTED BANDWIDTH 4.6 KHz 4.4 KHz 3.2 KHz 1.3 KHz 0.7KHz 0.6 KHz 0.5 KHz

NOTE: Listed bandwidth correction values are for Voltage mode, nominal resistive load.

BOP 20-20MC/DC-r4/031512

KEPCO, INC. z 131-38 SANFORD AVENUE z FLUSHING, NY. 11355 U.S.A. z TEL [phone] z FAX [phone]

email: [e-mail] z World Wide Web: http://www.kepcopower.com

In Current Mode the dynamic specifications are almost identical for all BOP MC and DC
models: 3-dB bandwidth of 4.9kHz and rise/ fall time of 72µs (lower bandwidth and higher rise/
fall time than standard BOP M and D models).

FIGURE 1. ASSEMBLY A1, EXTERNAL BANDWIDTH CORRECTION CAPACITOR LOCATIONS

2 BOP 20-20MC/031512