Document
Features
Switching Regulator
• Efficiency up to 95%, no heatsinks required • Pin compatible with LM78XX linears • Low profile (L/W/H=11.5 x 8.5 x 17.5mm) • Wide input range • Short circuit protection, thermal shutdown • Low ripple and noise • „L“ version with 90° pins
DC/DC Converter
R-78B-1.5(L)
RE CTS
RE CTS
y
w
ERS CO
ERS CO
Description
The R-78Bxx-1.5 series high efficiency switching regulators are ideally suited to replace 78xx linear regulators and are pin compatible. The efficiency of up to 95% means that very little energy is wasted as heat so there is no need for any heat sinks with their additional space and mounting costs. The L-Version with 90° pins allows direct replacement for laid-flat regulators where component height is at a premium. Low ripple and noise figures and a short circuit input current of typically only 10mA round off the specifications of this versatile converter series.
1.5 Amp SIP3
YEAR
3
arrant
Single Output
Selection Guide
Part Number
R-78B3.3-1.5 (1) R-78B5.0-1.5 (1) R-78B6.5-1.5 (1)
Input Voltage Range
[VDC]
4.75 - 18
6.5 - 18
8.0 - 18
Output Voltage [VDC]
3.3
5.0
6.5
Output Efficiency
Current
@ min Vin @ max. Vin
[A]
[%] [%]
1.5
91 88
1.5
94 92
1.5
95 93
Selection Guide (NRND, last time buy: 16th Nov 2020)
Part Number
R-78B1.5-1.5 (1) R-78B1.8-1.5 (1) R-78B2.5-1.5 (1)
Input Voltage Range
[VDC]
4.75 - 18
4.75 - 18
4.75 - 18
Output Voltage [VDC]
1.5
1.8
2.5
Output Efficiency
Current
@ min Vin @ max. Vin
[A]
[%] [%]
1.5
83 78
1.5
85 81
1.5
88 84
Model Numbering
R-78B__-1.5(L)
Output Voltage
Pinning
Output Current
Notes: Note1: add suffix “L” for 90° bent pins, e.g. R-78B5.0-1.5L
Specifications (measured @ Ta= 25°C, 10% minimum load, unless otherwise stated)
BASIC CHARACTERISTICS
Parameter
Condition
Min. Typ. Max.
Quiescent Current
nom. Vin= 12VDC
7mA 9mA
Internal Power Dissipation
Vout= 1.5VDC
0.65W
Internal Operating Frequency
nom. Vin= 12VDC
300kHz 340kHz 380kHz
Minimum Load (2)
0%
Output Ripple and Noise (3)
20MHz BW
15mVp-p 30mVp-p
Ref. Back Ripple Current
150mAp-p 200mAp-p
Absolute Maximum Capacitive Load
1 second start up, no external components <1 second start up + diode protection circuit
1000µF 6800µF
Notes: Note2: Operation under no load will not harm the converter, but specifications may not be met
A minimum load of 10mA is recommended Note3: Output Ripple and Noise is tested from 10% to 100% load continued on next page
COM CONVERT
RoHS 2+
compliant 10 from 10
M PLIANT PRODU
COM CONVERT
REACH
compliant
M PLIANT PRODU
EN55032 compliant IEC/EN60950-1 certified
PREFERRED ALTERNATIVES
Please consider these alternatives:
R-78B-2.0 Series
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REV.: 5/2020
I-1
R-78Bxx-1.5(L)
DC/DC Converter
Specifications (measured @ Ta= 25°C, 10% minimum load, unless otherwise stated)
Series
Efficiency vs. Vin (full load)
100
90
80
70
Efficiency [%]
60
50
40
30
20
10
0 4.75 7
9
11
13
Input Voltage [VDC]
6.5Vout 5Vout
3.3Vout 2.5Vout 1.8Vout 1.5Vout
15
17 18
Ripple vs. Vin (full load)
50
45
40
35
Ripple [mV]
30
25
20
15
10
5
0
4.75
7
9
11 13
Input Voltage [VDC]
6.5Vout 5Vout
3.3Vout 2.5Vout 1.8Vout 1.5Vout
15
17 18
Efficiency vs. Load (max. Vin)
Efficiency [%]
100 90 80 70 60 50 40 30 20 10 0
0
6.5Vout 5Vout
3.3Vout 2.5Vout 1.8Vout 1.5Vout
10 20 30 40 50 60 70 80 90 100
Output Load [%]
Ripple vs. Load (max. Vin)
Ripple [mV]
50
6.5Vout
45
5Vout 3.3Vout
40
2.5Vout
1.8Vout
35
1.5Vout
30
25
20
15
10
5
0 0 10 20 30 40 50 60 70 80 90 100
Output Load [%]
Efficiency vs. Load (min. Vin)
Efficiency [%]
100 90 80 70 60 50 40 30 20 10 0
0
6.5Vout 5Vout
3.3Vout 2.5Vout 1.8Vout 1.5Vout
10 20 30 40 50 60 70 80 90 100
Output Load [%]
Ripple [mV]
Ripple vs. Load (min. Vin)
50
6.5Vout
5Vout
45
3.3, 2.5Vout
40
1.8, 1.5Vout
35
30
25
20
15
10
5
0 0 10 20 30 40 50 60 70 80 90 100
Output Load [%]
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REV.: 5/2020
I-2
R-78Bxx-1.5(L)
DC/DC Converter
Specifications (measured @ Ta= 25°C, 10% minimum load, unless otherwise stated)
Series
REGULATIONS Parameter
Output Accuracy Line Regulation Load Regulation
Transient Response
Condition 100% load low line to high line, 100% load 10% to 100% load 100% <-> 50% load Recovery Time
Value ±2.0% typ / ±3.0% max. ±0.3% typ. / ±0.5% max. ±0.6% typ. / ±0.8% max. ±80mV typ. / ±120mV max. 1.0ms min. / 1.5ms typ.
PROTECTIONS Parameter
Short Circuit Protection (SCP) Short Circuit Input Current
Optional Diode Protection Circuit
Condition below 100mW nom. Vin= 12VDC
Optional Protection 1:
Value
continuous, automatic recovery
+Vin
R-78Bxx-1.5
+Vin
+Vout
1+0V0oumt A max.
GND
Optional Protection 2:
Add a blocking diode to Vout if current can flow backwards into the output, as this can damage the converter when it is powered down. +Vin
The diode can either be fitted across the device if the source is low impedance or .