Datasheet

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ULS 30-Watt Series
Sixteenth-brick DOSA-Compatible,
Isolated DC/DC Converters
MDC_ULS-30W_C07 Page 28 of 30
Through-hole Soldering Guidelines
Murata Power Solutions recommends the TH soldering specifi cations below when install-
ing these converters. These specifi cations vary depending on the solder type. Exceeding
these specifi cations may cause damage to the product. Your production environment may
differ; therefore please thoroughly review these guidelines with your process engineers.
Wave Solder Operations for through-hole mounted
products (THMT)
For Sn/Ag/Cu based solders:
Maximum Preheat Temperature 115° C.
Maximum Pot Temperature 270° C.
Maximum Solder Dwell Time 7 seconds
For Sn/Pb based solders:
Maximum Preheat Temperature 105° C.
Maximum Pot Temperature 250° C.
Maximum Solder Dwell Time 6 seconds
SMT Refl ow Soldering Guidelines
The surface-mount refl ow solder profi le shown below is suitable for SAC305 type lead-
free solders. This graph should be used only as a guideline. Many other factors infl uence
the success of SMT refl ow soldering. Since your production environment may differ,
please thoroughly review these guidelines with your process engineers.
Trimming by Using an External Voltage Source
1. The easiest way to trim the output using an external voltage source is to
drive the Trim pin directly from a variable source. The following equation can
be used to calculate the voltage at the Trim pin.
Vo is the output voltage you want; Vonominal is the nominal output voltage;
Vtrim is the voltage that should appear at the trim pin.
2. If the purpose of trimming is to compensate voltage drop of power path
from converter to the Load, you may separately connect the sense pin directly
to the load. It’s much easier than real time adjusting trim voltage.
3. CAUTION: To avoid unplanned power down cycles, do not exceed EITHER
the maximum output voltage OR the maximum output power when setting
the trim. If the output voltage is excessive, the OVP circuit may shut down the
converter. If the maximum power is exceeded, the converter may enter current
limiting. If the power is exceeded for an extended period, the converter may
overheat and encounter overtemperature shut down. Be careful of external
electrical noise. The Trim input is a sensitive input to the converter’s feedback
control loop. Excessive electrical noise may cause instability or oscillation.
Vonominal
Vo
Vtrim = 2 x 1.24 x
− 1.24
Figure 8. Trimming with an external source
LOAD
+VOUT
+VIN
–VIN
ON/OFF
CONTROL
TRIM
+SENSE
–VOUT
External
source
–SENSE
+
–