DC/DC Converter

ECO-2

REV.: 2/2017

www.recom-power.com

REC30-Z

Series

BASIC CHARACTERISTICS

Parameter

Condition

Min.

Typ.

Max.

Input Voltage Range

nom. Vin= 24V

nom. Vin= 48V

9VDC

18VDC

36VDC

75VDC

Start/up Time

20ms

Under Voltage Lockout

nom. Vin= 24V

DC-DC ON

DC-DC OFF

8.3VDC

7.9VDC

nom. Vin= 48V

DC-DC ON

DC-DC OFF

17.4VDC

16.7VDC

Output Voltage Trimming

see calculation below

±10%

Remote ON/OFF

DC-DC ON

DC-DC OFF

Open or 3V<Vr<12V

Short or 0V<Vr<1.2V

Operating Frequency

350kHz

Minimum Load

0%

100mVp-p

continued on next page

Notes:

Note2: Ripple and Noise is measured with a 20MHz bandwidth and a 0.1µF ceramic capacitor.

Output Voltage Trimming

Trim Calculation

Trim UP

Trim DOWN

Vref

+Vout

Trim

R1

R3

R2

Vref

-Vout

Trim

R1

R3

R2

Vref

+Vout

Trim

R1

R3

R2

Vref

-Vout

Trim

R1

R3

R2

Vout

3.4V

5.1V

12V

15V

R1

2.1 k

Ω

2.55 k

Ω

9.53 k

Ω

9.09 k

Ω

R2

1.198 k

Ω 2.449 kΩ 2.498 kΩ 1.810 kΩ

R3

6.8 k

Ω

9.76 k

Ω

16.9 k

Ω

13 k

Ω

Vref

1.24 V

2.5 V

q a*R2 r-R3=kΩ

DVout = Output Voltage Trim

R2 - a

= trim up resistor

q b*R1 r- R3=kΩ

a

= trim up factor

R1 - b

b

= trim down factor

a =

q Vref r*R1=kΩ

DVout - Vref

b =

qDVout -Vrefr*R2=kΩ

Vref

Practical Example:

a =

q 2.5V r*2.55kΩ=2.05kΩ

5.61V - 2.5V

q 2.05kΩ*2.449kΩ r-9.76kΩ= 2.826kΩ

2.449kΩ - 2.05kΩ

Trim Up:

Vout = 5.1V,

DVout = 10% (5.61V), Vref= 2.5V

Trim down:

Vout = 5.1V,

DVout = -10% (4.59V), Vref= 2.5V

b =

q4.59V -2.5Vr*2.449kΩ= 2.047kΩ

2.5V

q2.047kΩ*2.55kΩr- 9.76kΩ=0.617kΩ

2.55k

Ω - 2.047kΩ