• Efficiency up to 96%, no need for heatsinks
• 4.5 - 36VDC wide input voltage
• -40°C to +90°C ambient operation without
derating
• Pin compatible with 78 series regulators
• Non isolated DC/DC converter
• Undervoltage and short circuit protection
Features
Switching
Regulator
Description
The R-78K-0.5 series is a switching regulator module that has been designed to offer all the advantages
of a switching regulator (high efficiency, wide input range, accurate output voltage regulation) but with
a low cost for production quantities. Due to the R-78K-0.5’s high efficiency of up to 96%, no heat-sink
is required, and full load operation from -40 to 90°C is possible. The compact TO-220 compatible SIP3
package measures only 11.5 x 7.55 x 10.2mm, so it saves precious board space.
DC/DC Converter
R-78K-0.5
0.5 Amp
SIP3
Single Output
Selection Guide
Efficiency
@ min. Vin
@ max. Vin
[%]
[%]
83
66
4.5 - 36
3.3
500
89
80
R-78K5.0-0.5
6.5 - 36
5
500
92
85
6.5
500
93
86
12 - 36
9
500
94
89
R-78K12-0.5
15 - 36
12
500
95
91
R-78K15-0.5
18 - 36
15
500
96
92
C O N V ER
T
RoHS 2 +
compliant
M
R-78K9.0-0.5
M
10 from 10
PL
D
IA N
T PRO
U
C
O
M
CO NVE R
T
REACH
compliant
CO
8 - 36
O
CO
R-78K6.5-0.5
C
M
TS
R-78K3.3-0.5
P
C
75
RE
70
87
TS
85
500
C
500
2.5
S
1.8
4.5 - 36
R
4.5 - 36
R-78K2.5-0.5
E
R-78K1.8-0.5
S
Output
Current
[mA]
500
R
Output
Voltage
[VDC]
1.5
E
R-78K1.5-0.5
Input
Voltage Range
[VDC]
4.5 - 36
RE
Part
Number
U
LIA
D
N T PRO
IEC/EN62368-1 3rd Edition certified
EN55032 compliant
Model Numbering
R-78K
Output Current
Output Voltage
Specifications
ABSOLUTE MAX RATINGS (exceeding these ratings may damage the device)
Parameter
Condition
Maximum Input Voltage Slew Rate (1)
+VIN to GND
Min.
Typ.
Max.
Case Temperature
-40°C
10VDC/µs
115°C
Storage Temperature
-50°C
125°C
Notes:
Note1: At higher slew rates or hard plugging, add 27µF E-Cap between +Vin and GND,
especially when Vin is >18VDC
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REV.: 0/2023
I-1
R-78K-0.5
Series
DC/DC Converter
Specifications (measured @ Ta= -40°C to +90°C, V
= 24VDC, full load and after warm-up unless otherwise stated)
IN
BASIC CHARACTERISTICS
Parameter
Condition
Min.
R-78K1.5-0.5, R-78K1.8-0.5,
R-78K2.5-0.5, R-78K3.3-0.5
R-78K5-0.5
R-78K6.5-0.5
Input Under Voltage Lockout (UVLO)
R-78K9-0.5
R-78K12-0.5
R-78K15-0.5
Typ.
Max.
DC-DC ON
5.15VDC
5.45VDC
DC-DC OFF
3.6VDC
3.9VDC
DC-DC ON
5.15VDC
5.45VDC
DC-DC OFF
4.6VDC
4.9VDC
DC-DC ON
7.0VDC
7.5VDC
DC-DC OFF
6.3VDC
6.7VDC
DC-DC ON
10.2VDC
10.8VDC
DC-DC OFF
9.1VDC
9.7VDC
DC-DC ON
13.8VDC
14.4VDC
DC-DC OFF
12.4VDC
13.0VDC
DC-DC ON
16.9VDC
17.5VDC
DC-DC OFF
15.2VDC
15.8VDC
1mA
Quiescent Current
600kHz
Internal Switching Frequency
Minimum Load
700kHz
800kHz
0%
Output Ripple and Noise
20MHz BW
R-78K1.5-0.5 - R-78K1.8-0.5
30mVp-p
R-78K2.5-0.5 - R-78K3.3-0.5
60mVp-p
R-78K5-0.5 - R-78K6.5-0.5
85mVp-p
R-78K9-0.5 - R-78K15-0.5
100mVp-p
R-78K1.5-0.5
Efficiency vs. Load
Power Dissipation vs. Load
0.4
100
Power Dissipation [W]
Efficiency [%]
80
70
60
50
4.5VDC
12VDC
24VDC
36VDC
40
30
20
0.3
0.25
0.2
0.15
0.1
0.05
0
10
0
4.5VDC
12VDC
24VDC
36VDC
0.35
90
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
continued on next page
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REV.: 0/2023
I-2
R-78K-0.5
Series
DC/DC Converter
Specifications (measured @ Ta= -40°C to +90°C, V
R-78K1.8-0.5
= 24VDC, full load and after warm-up unless otherwise stated)
IN
Efficiency vs. Load
Power Dissipation vs. Load
0.4
100
Power Dissipation [W]
Efficiency [%]
80
70
60
50
4.5VDC
12VDC
24VDC
36VDC
40
30
20
0.3
0.25
0.2
0.15
0.1
0.05
0
10
0
4.5VDC
12VDC
24VDC
36VDC
0.35
90
0
10
20
30
40
50
60
70
80
90
100
80
90
100
80
90
100
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
R-78K2.5-0.5
Efficiency vs. Load
Power Dissipation vs. Load
0.4
100
Power Dissipation [W]
Efficiency [%]
80
70
60
50
4.5VDC
12VDC
24VDC
36VDC
40
30
20
0.3
0.25
0.2
0.15
0.1
0.05
0
10
0
4.5VDC
12VDC
24VDC
36VDC
0.35
90
0
10
20
30
40
50
60
70
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
R-78K3.3-0.5
Efficiency vs. Load
Power Dissipation vs. Load
0.4
100
Power Dissipation [W]
Efficiency [%]
80
70
60
50
4.5VDC
12VDC
24VDC
36VDC
40
30
20
0.3
0.25
0.2
0.15
0.1
0.05
0
10
0
4.5VDC
12VDC
24VDC
36VDC
0.35
90
0
10
20
30
40
50
60
70
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
continued on next page
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REV.: 0/2023
I-3
R-78K-0.5
Series
DC/DC Converter
Specifications (measured @ Ta= -40°C to +90°C, V
R-78K5.0-0.5
= 24VDC, full load and after warm-up unless otherwise stated)
IN
Efficiency vs. Load
Power Dissipation vs. Load
0.5
100
Power Dissipation [W]
90
Efficiency [%]
80
70
60
50
6.5VDC
12VDC
24VDC
36VDC
40
30
20
0.40
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
10
0
6.5VDC
12VDC
24VDC
36VDC
0.45
0
10
20
30
40
50
60
70
80
90
100
80
90
100
80
90
100
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
R-78K6.5-0.5
Efficiency vs. Load
Power Dissipation vs. Load
0.6
100
Power Dissipation [W]
Efficiency [%]
80
70
60
50
8VDC
12VDC
24VDC
36VDC
40
30
20
0.4
0.3
0.2
0.1
0
10
0
8VDC
12VDC
24VDC
36VDC
0.5
90
0
10
20
30
40
50
60
70
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
R-78K9.0-0.5
Efficiency vs. Load
Power Dissipation vs. Load
0.6
100
Power Dissipation [W]
90
Efficiency [%]
80
70
60
50
12VDC
18VDC
24VDC
36VDC
40
30
20
0.4
0.3
0.2
0.1
0
10
0
12VDC
18VDC
24VDC
36VDC
0.5
0
10
20
30
40
50
60
70
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
continued on next page
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I-4
R-78K-0.5
Series
DC/DC Converter
Specifications (measured @ Ta= -40°C to +90°C, V
R-78K12-0.5
= 24VDC, full load and after warm-up unless otherwise stated)
IN
Efficiency vs. Load
Power Dissipation vs. Load
0.6
100
Power Dissipation [W]
Efficiency [%]
80
70
60
50
15VDC
18VDC
24VDC
36VDC
40
30
20
0.4
0.3
0.2
0.1
0
10
0
15VDC
18VDC
24VDC
36VDC
0.5
90
0
10
20
30
40
50
60
70
80
90
100
80
90
100
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
R-78K15-0.5
Efficiency vs. Load
Power Dissipation vs. Load
0.6
100
Power Dissipation [W]
Efficiency [%]
80
70
60
50
18VDC
24VDC
30VDC
36VDC
40
30
20
0.4
0.3
0.2
0.1
0
10
0
18VDC
24VDC
30VDC
36VDC
0.5
90
0
10
20
30
40
50
60
70
Output Load [%]
0
10
20
30
40
50
60
70
80
90
100
Output Load [%]
REGULATIONS
Parameter
Condition
Output Accuracy
Value
±1.7% typ. / ±2.7% max.
Line Regulation
low line to high line, full load
Load Regulation
0% to 100%
10% to 100% load
±0.3% max.
1.7% typ. / 2.7% max.
1.5% max.
PROTECTIONS
Parameter
Condition
Short Circuit Protection (SCP)
Value
continuous, automatic recovery
Short Circuit Input Current
30mA max.
continued on next page
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REV.: 0/2023
I-5
R-78K-0.5
DC/DC Converter
Specifications
+Vin
+Vin
(measured @ Ta= -40°C to +90°C, VIN= 24VDC, full load and after warm-up unless otherwise stated)
Optional Diode Protection Circuit
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.
Optional Protection 1:
+Vin
+Vin
Optional
GND
R-78Kxx-0.5
+Vin
+Vout
+Vout
R-78Kxx-0.5
+Vout
+Vout
GND
Protection 2:
+Vin
Series
GND
R-78Kxx-0.5
+Vout
GND
+Vout= +Vout - 0.3V
GND
The diode can either be fitted
across the device if the source is
low impedance or fitted in series
with the output (recommended).
+Vin
+Vin
R-78Kxx-0.5
GND
GND
GND
GND
+Vout= +Vout - 0.3V
+Vout
GND
GND
GND
ENVIRONMENTAL
Parameter
Condition
Value
refer to “Derating Graph”
Operating Temperature Range
-40°C to +90°C
Maximum Case Temperature
+115°C
Temperature Coefficient
0.01%/K
Operating Humidity
non-condensing
MTBF
95% RH max.
R-78K1.5-0.5
7517 x 10³ hours
R-78K1.8-0.5
6644 x 10³ hours
R-78K2.5-0.5
7538 x 10³ hours
R-78K3.3-0.5
6762 x 10³ hours
R-78K5.0-0.5
9861 x 10³ hours
R-78K6.5-0.5,
R-78K9.0-0.5
3361 x 10³ hours
R-78K12-0.5
4523 x 10³ hours
R-78K15-0.5
3485 x 10³ hours
according to MIL-HDBK-217F, G.B., +25°C
Vibration
10-55Hz, 2G, 30min along X,Y and Z axis
Derating Graph
(@ Chamber and natural convection 0.1m/s, over Vin)
R-78K1.8-0.5
100
100
90
90
80
80
70
70
Output Load [%]
Output Load [%]
R-78K1.5-0.5
60
50
40
30
20
10
60
50
40
30
20
5 - 36VDC
5VDC
12VDC
24VDC
36VDC
10
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
Ambient Temperature [°C]
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
81
Ambient Temperature [°C]
continued on next page
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REV.: 0/2023
I-6
R-78K-0.5
Series
DC/DC Converter
Specifications (measured @ Ta= -40°C to +90°C, V
= 24VDC, full load and after warm-up unless otherwise stated)
IN
R-78K5.0-0.5
100
100
90
90
80
80
70
70
Output Load [%]
Output Load [%]
R-78K2.5-0.5 & R-78K3.3-0.5
60
50
40
30
20
5VDC
12VDC
24VDC
36VDC
60
50
40
30
20
10
10
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
73
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
74 84
R-78K6.5-0.5
R-78K9.0-0.5
Ambient Temperature [°C]
100
100
90
90
80
80
70
70
Output Load [%]
Output Load [%]
Ambient Temperature [°C]
60
50
40
30
20
8VDC
12VDC
24VDC
36VDC
60
50
40
30
12VDC
24VDC
36VDC
20
10
10
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
69 77 87
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
66 76 86
R-78K12.0-0.5
R-78K15.0-0.5
Ambient Temperature [°C]
Ambient Temperature [°C]
100
100
90
90
80
80
70
70
Output Load [%]
Output Load [%]
6.5/12VDC
18VDC
36VDC
60
50
40
30
18VDC
24VDC
36VDC
60
50
40
30
20
20
10
10
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
62 76 82
Ambient Temperature [°C]
18VDC
24VDC
36VDC
0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110
54
72
Ambient Temperature [°C]
continued on next page
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REV.: 0/2023
I-7
R-78K-0.5
Series
DC/DC Converter
Specifications (measured @ Ta= -40°C to +90°C, V
= 24VDC, full load and after warm-up unless otherwise stated)
IN
SAFETY AND CERTIFICATIONS (PENDING)
Certificate Type (Safety)
Report Number
Audio/Video, information and communication technology equipment - Part 1: Safety requirements
CN21UWPW002
RoHS2
Standard
IEC62368-1:2018 3rd Edition
RoHS 2011/65/EU + AM2015/863
EMC Compliance
Condition
Standard / Criterion
with external filter refer to “EMC filtering”
Electromagnetic compatibility of multimedia equipment - Emission requirements
EN55032, Class B
EMC filtering suggestion according to EN55032
C3
L1
+Vin
R-78K
+Vin
C1
+Vout
+Vout
GND
C2
GND
GND
Component List Class B
C1/C2
C3
L1
10µF
1nF
100µH
DIMENSION AND PHYSICAL CHARACTERISTICS
Parameter
Type
Value
Material
case
potting
PCB
black plastic, (UL94 V-0)
PU, (UL94 V-0)
FR4, (UL94 V-0)
Dimension (LxWxH)
11.5 x 7.55 x 10.2mm
Weight
1.7g typ.
Dimension Drawing (mm)
embossed logo
7.55
2X 2.54
2.0
3.21
1 2 3
Bottom View
�0.64±0.1
Recommended Footprint Details
2.54
4.1
0.5
10.2
11.5
Top View
1 2 3
2.54
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REV.: 0/2023
Pinning Information
Pin #
Single
1
+VIN
2
GND
3
+VOUT
Tolerance:
xx.x = ±0.5mm
xx.xx = ±0.25mm
I-8
R-78K-0.5
Series
DC/DC Converter
Specifications (measured @ Ta= -40°C to +90°C, V
= 24VDC, full load and after warm-up unless otherwise stated)
IN
PACKAGING INFORMATION
Parameter
Type
Value
Packaging Dimension (LxWxH)
tube
520.0 x 9.2 x 19.0mm
Packaging Quantity
43pcs
Storage Temperature Range
Storage Humidity
-50°C to +125°C
non-condensing
95% RH max.
The product information and specifications may be subject to changes even without prior written notice.The product has been designed for various applications; its suitability lies in the responsibility of each customer. The
products are not authorized for use in safety-critical applications without RECOM’s explicit written consent. A safety-critical application is an application where a failure may reasonably be expected to endanger or cause
loss of life, inflict bodily harm or damage property. The applicant shall indemnify and hold harmless RECOM, its affiliated companies and its representatives against any damage claims in connection with the unauthorized
use of RECOM products in such safety-critical applications.
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REV.: 0/2023
I-9
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
RECOM:
R-78K1.5-0.5 R-78K12-0.5 R-78K6.5-0.5 R-78K2.5-0.5 R-78K15-0.5 R-78K3.3-0.5 R-78K5.0-0.5 R-78K9.0-0.5
R-78K1.8-0.5
