Bel Power Solutions point-of-load converters are
recommended for use with regulated bus converters in an
Intermediate Bus Architecture (IBA). The YS12S16 non-
isolated DC-DC converters deliver up to 16 A of output
current in an industry-standard surface-mount package.
Operating from a 9.6-14 VDC input, the YS12S16
converters are ideal choices for Intermediate Bus
Architectures where point-of-load power delivery is
generally a requirement. They provide an extremely tight
regulated programmable output voltage of 0.7525 V to 5.5
V.
RoHS lead-free solder and lead-solder-exempted products
are available
Delivers up to 16 A (88 W)
Extended input range 9.6 V – 14 V
High efficiency (0.948 at 5 V output)
Surface-mount package
Industry-standard footprint and pinout
Small size and low profile: 1.30” x 0.53” x 0.314” (33.02 x
13.46 x 7.98 mm)
Weight: 0.23 oz [6.50 g]
Coplanarity less than 0.003”, maximum
Synchronous Buck Converter topology
Start-up into pre-biased output
No minimum load required
Programmable output voltage via external resistor
Operating ambient temperature: -40 °C to 85 °C
Remote output sense
Remote ON/OFF (positive or negative)
Fixed-frequency operation
Auto-reset output overcurrent protection
Auto-reset overtemperature protection
High reliability, MTBF approx. 27.2 Million Hours
calculated per Telcordia TR-332, Method I Case 1
All materials meet UL94, V-0 flammability rating
UL 60950 recognition in U.S. & Canada, and DEMKO
certification per IEC/EN 60950
The YS12S16 converters provide exceptional thermal
performance, even in high temperature environments with
minimal airflow. This is accomplished through the use of
advanced circuitry, packaging, and processing
techniques to achieve a design possessing ultra-high
efficiency, excellent thermal management and a very low
body profile.
The low body profile and the preclusion of heat sinks
minimize impedance to system airflow, thus enhancing
cooling for both upstream and downstream devices. The
use of 100% automation for assembly, coupled with
advanced power electronics and thermal design, results
in a product with extremely high reliability.
Intermediate Bus Architectures
Telecommunications
Data communications
Distributed Power Architectures
Servers, workstations
High efficiency – no heat sink required
Reduces total solution board area
Tape and reel packing
Compatible with pick & place equipment
Minimizes part numbers in inventory
Low cost
North America
+1-866.513.2839
Asia-Pacific
+86.755.29885888
Europe, Middle East
+353 61 225 977
tech.support@psbel.com
© 2015 Bel Power Solutions, Inc.
BCD.00645_AA
YS12S16 DC-DC Converter
Conditions: T
A
= 25 ºC, Airflow = 300 LFM (1.5 m/s), Vin = 12 VDC, Vout = 0.7525 – 5.5 V, unless otherwise specified.
PARAMETER
Absolute Maximum Ratings
Input Voltage
Operating Ambient Temperature
Storage Temperature
Feature Characteristics
Switching Frequency
Output Voltage Trim Range
Turn-On Delay Time
2
1
1
NOTES
Continuous
MIN
-0.3
-40
-55
TYP
MAX
15
85
125
UNITS
VDC
°C
°C
kHz
300
By external resistor, See Trim Table 1
Percent of V
OUT
(
NOM
)
Full resistive load
From Vin = Vin(min) to Vo=0.1* Vo(nom)
From 0.1*Vo(nom) to 0.9*Vo(nom)
Converter Off
Converter On
Converter Off
Converter On
-5
2.4
2.4
-5
9.6
12
9
8.5
16 ADC Out @ 9.6 VDC In
V
OUT
= 5.0 VDC
V
OUT
= 3.3 VDC
V
OUT
= 2.5 VDC
V
OUT
= 2.0 VDC
V
OUT
= 1.8 VDC
V
OUT
= 1.5 VDC
V
OUT
= 1.2 VDC
V
OUT
= 1.0 VDC
V
OUT
= 0.7525 VDC
8.9
6
4.6
3.8
3.4
2.9
2.4
2.1
1.7
3
V
OUT
= 5.0 VDC
V
OUT
= 3.3 VDC
V
OUT
= 2.5 VDC
V
OUT
= 2.0 VDC
V
OUT
= 1.8 VDC
V
OUT
= 1.5 VDC
V
OUT
= 1.2 VDC
V
OUT
= 1.0 VDC
V
OUT
= 0.7525 VDC
83
63
53
47
45
43
41
39
35
60
43
35
35
35
33
3
3
4
0.8
Vin
Vin
0.8
14
0.7525
5.5
0.5
VDC
VDC
ms
ms
ms
VDC
VDC
VDC
VDC
VDC
VDC
VDC
ADC
ADC
ADC
ADC
ADC
ADC
ADC
ADC
ADC
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
P-P
mA
P-P
mA
P-P
mA
P-P
mA
P-P
mA
P-P
Remote Sense Compensation
With Vin = (Converter Enabled, then Vin applied)
Rise time (Full resistive load)
ON/OFF Control (Positive Logic)
3
ON/OFF Control (Negative Logic)
3
Input Characteristics
Operating Input Voltage Range
Input Under Voltage Lockout
Turn-on Threshold
Turn-off Threshold
Maximum Input Current
2
With Enable (Vin = Vin(nom) applied, then enabled) From enable to Vo= 0.1*Vo(nom)
Input Stand-by Current (Converter disabled)
Input No Load Current (Converter enabled)
Input Reflected-Ripple Current -
i
s
See Fig. E for setup. (BW = 20 MHz)
V
OUT
= 5.0 VDC
V
OUT
= 3.3 VDC
V
OUT
= 2.5 VDC
V
OUT
= 2.0 VDC
V
OUT
= 1.8 VDC
V
OUT
= 1.5 VDC
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© 2015 Bel Power Solutions, Inc.
BCD.00645_AA
YS12S16 DC-DC Converter
V
OUT
= 1.2 VDC
V
OUT
= 1.0 VDC
V
OUT
= 0.7525 VDC
Input Voltage Ripple Rejection
Output Characteristics
Output Voltage Set Point (no load)
Output Regulation
Over Line
Over Load
Output Voltage Range
(Over all operating input voltage, resistive load
and temperature conditions until end of life )
Output Ripple and Noise - 20MHz bandwidth
Peak-to-Peak
Peak-to-Peak
External Load Capacitance
Min ESR > 1mΩ
Min ESR > 10 mΩ
Output Current Range
Output Current Limit Inception (I
OUT
)
Output Short- Circuit Current , RMS Value
Dynamic Response
Load current change from 8A – 16A, di/dt = 5 A/μS
Settling Time (V
OUT
< 10% peak deviation)
Unloading current change from 16A – 8A, di/dt = -5 A/μS
Settling Time (V
OUT
< 10% peak deviation)
Efficiency
Full load (16A)
V
OUT
= 5.0 VDC
V
OUT
= 3.3 VDC
V
OUT
= 2.5 VDC
V
OUT
= 2.0 VDC
V
OUT
= 1.8 VDC
V
OUT
= 1.5 VDC
V
OUT
= 1.2 VDC
V
OUT
= 1.0 VDC
V
OUT
= 0.7525 VDC
94.8
92.5
90.5
89.0
88.0
86.0
84.0
80.5
77.0
%
%
%
%
%
%
%
%
%
Short=10 mΩ, continuous
Co = 100μF ceramic + 470
μF
POS
Co = 100
μF
ceramic + 470
μF
POS
0
25
4
140
45
140
45
Full resistive load
From no load to full load
-2.5
Over line, load and temperature (Fig. E)
V
OUT
= 0.7525 VDC
V
OUT
= 5.0 VDC
Plus full load (resistive)
1,000
5,000
16
μF
μF
A
A
A
mV
µs
mV
µs
12
40
19
65
mV
P-P
mV
P-P
0.5
5
+2.5
mV
mV
%Vout
-1.5
Vout
+1.5
%Vout
120 Hz
23
21
19
72
mA
P-P
mA
P-P
mA
P-P
dB
Notes:
1
The output voltage should not exceed 5.5V (taking into account both the programming and remote sense compensation).
2
Note that start-up time is the sum of turn-on delay time and rise time.
3
The converter is on if ON/OFF pin is left open.
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© 2015 Bel Power Solutions, Inc.
BCD.00645_AA
YS12S16 DC-DC Converter
Input and Output Impedance
The YS12S16 converter should be connected via a low impedance to the DC power source. In many applications, the
inductance associated with the distribution from the power source to the input of the converter can affect the stability
of the converter. It is recommended to use decoupling capacitors (minimum 47
μF)
placed as close as possible to the
converter input pins in order to ensure stability of the converter and reduce input ripple voltage. Internally, the
converter has 30
μF
(low ESR ceramics) of input capacitance.
In a typical application, low - ESR tantalum or POS capacitors will be sufficient to provide adequate ripple voltage
filtering at the input of the converter. However, very low ESR ceramic capacitors 47
μF-100 μF
are recommended at
the input of the converter in order to minimize the input ripple voltage. They should be placed as close as possible to
the input pins of the converter.
The YS12S16 has been designed for stable operation with or without external capacitance. Low ESR ceramic
capacitors placed as close as possible to the load (minimum 47
μF)
are recommended for improved transient
performance and lower output voltage ripple.
It is important to keep low resistance and low inductance PCB traces for connecting load to the output pins of the
converter in order to maintain good load regulation.
ON/OFF (Pin 1)
The ON/OFF pin is used to turn the power converter on or off remotely via a system signal. There are two remote
control options available, positive logic (standard option) and negative logic, and both are referenced to GND. The
typical connections are shown in Fig. A.
The positive logic version turns the converter on when the ON/OFF pin is at a logic high or left open, and turns the
converter off when at a logic low or shorted to GND.
Vin
R*
Y-Series
Converter
(Top View)
SENSE
ON/OFF
Vin
Vout
Rload
GND
CONTROL
INPUT
TRIM
R* is for negative logic option only
Fig. A:
Circuit configuration for ON/OFF function.
The negative logic version turns the converter on when the ON/OFF pin is at logic low or left open, and turns the
converter off when the ON/OFF pin is at a logic high or connected to Vin.
The ON/OFF pin is internally pulled-up to Vin for a positive logic version, and pulled-down for a negative logic version.
A TTL or CMOS logic gate, open collector (open drain) transistor can be used to drive the ON/OFF pin. When using
open collector (open drain) transistor with a negative logic option, add a pull-up resistor (R*) of 75K to Vin as shown in
Fig. A;
This device must be capable of:
-
sinking up to 0.2 mA at a low level voltage of
0.8 V
-
sourcing up to 0.25 mA at a high logic level of 2.3 V – 5 V
-
sourcing up to 0.75 mA when connected to Vin.
Remote Sense (Pin 2)
The remote sense feature of the converter compensates for voltage drops occurring only between Vout pin (Pin 4) of
the converter and the load. The SENSE (Pin 2) pin should be connected at the load or at the point where regulation is
required (see Fig. B). There is no sense feature on the output GND return pin, where the solid ground plane should
provide low voltage drop.
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© 2015 Bel Power Solutions, Inc.
BCD.00645_AA
YS12S16 DC-DC Converter
If remote sensing is not required, the SENSE pin must be connected to the Vout pin (Pin 4) to ensure the converter
will regulate at the specified output voltage. If these connections are not made, the converter will deliver an output
voltage that is slightly higher than the specified value.
Vin
Y-Series
Converter
(Top View)
SENSE
Rw
ON/OFF
Vin
Vout
Rload
GND
TRIM
Rw
Fig. B:
Remote sense circuit configuration.
Because the sense lead carries minimal current, large trace on the end-user board are not required. However, sense
trace should be located close to a ground plane to minimize system noise and insure optimum performance.
When utilizing the remote sense feature, care must be taken not to exceed the maximum allowable output power
capability of the converter, equal to the product of the nominal output voltage and the allowable output current for the
given conditions.
When using remote sense, the output voltage at the converter can be increased up to 0.5 V above the nominal rating
in order to maintain the required voltage across the load. Therefore, the designer must, if necessary, decrease the
maximum current (originally obtained from the derating curves) by the same percentage to ensure the converter’s
actual output power remains at or below the maximum allowable output power.
Output Voltage Programming (Pin 3)
The output voltage can be programmed from
0.7525 V to 5.5 V by connecting an external resistor between TRIM pin (Pin 3) and GND pin (Pin 5); see Fig. C.
A trim resistor, R
TRIM
, for a desired output voltage can be calculated using the following equation:
R
TRIM
½
where,
10.5
1
(V
O -REQ
- 0.7525)
[k]
R
TRIM
½
Required value of trim resistor [k]
V
O
REQ
½
Desired (trimmed) output voltage [V]
Vin
Y-Series
Converter
(Top View)
SENSE
ON/OFF
Vin
Vout
Rload
GND
TRIM
R
TRIM
Fig. C:
Configuration for programming output voltage.
Note that the tolerance of a trim resistor directly affects the output voltage tolerance. It is recommended to use
standard 1% or 0.5% resistors; for tighter tolerance, two resistors in parallel are recommended rather than one
standard value from Table 1.
Ground pin of the trim resistor should be connected directly to the converter GND pin (Pin 5) with no voltage drop in
between. Table 1 provides the trim resistor values for popular output voltages.
866.513.2839
tech.support@psbel.com
© 2015 Bel Power Solutions, Inc.
BCD.00645_AA
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