User manual

AJUSTABLE STEP-DOWN CONVERTER 1 Amp, WIDE INPUT RANGE
Specifications refer to the standard application circuit at Ta: 25°C
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These operating instructions are published by: Conrad Electronic SE, Klaus-Conrad-Straße 1, D-92240 Hirschau/Germany
The operating instructions reflect the current technical specifications at time of print. We reserve the right to change the technical
or physical specifications. © Copyright 2010 by Conrad Electronic SE.
*04/10-MA
Note:
This converter is a “non-CE-checked” component. The utilisation must comply with the CE norms.
Standard application: Standard application:
P1
step down conv. W-78 adj.
AC
AC
+
ENA
P1
step down conv. W-78 adj.
AC
AC
+
ENA
+
Uout
ACV-IN
Type: W78 - ADJ
Item No: 16 78 33
e.g. 1A slow blow
inc. / dec.
output voltage
ENA:
enable / disable
shutdown
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Here is a simple calculation of the required minimal secondary transformer voltage at maximum load.
Set this voltage equal to the desired DC-output voltage plus three volt (e.g. 5V Uout + 3V = 8V min. ACV-IN).
6.9 35 V=
6.5 V~
24.75 V~
3.0 3.3 to 12 13
V=
0.07 0.2 %
0.9 0.2 %
150
7 45
mVpp
1.1 W
3.2 8.5 mA
18 50
88.4 %
0 1000 mA
Min. Typ. Max. UnitsParameter:
DC Input Voltage Range
AC Input Voltage RMS (3.3V output voltage at max. load)
AC Input Voltage RMS
Output Voltage (adj)
Line Voltage Regulation (Uin = min. to max. at 1A)
Load Regulation (0 to 1000 mA at Uin =DC 25V)
Transient Recovery Time (100% <-> 50% load)
Ripple & Noise (1000 mA)
Internal Power Dissipation (Uin = 24.75 V~ at max. load)
Quiescent Current
Shutdown (ENA) Quiescent Current
Effeciency
Output Current
µA
µsec
1200 1500 1800 mA
13 16 20 ms
0.0115 0.012
400 500 600 kHz
6.0 6.2 V=
330 mV
135 162
14
-40
+65
-40
+105
-40 +85
Output Current Limit
Current Limit Hiccup Time
Temperature Coefficient
Switching Frequency
Undervoltage Lockout
Undervoltage Hysteresis
Thermal Shutdown (internal junction temperature)
Thermal Shutdown Hysteresis
Operating Temperature Range
Operating Junction Temperature Range
Storage Temperature Range
°C
°C
°C
°C
°C
%/°C
85 %Rel. Air Humidity (non-condensing)
Dimensions (L-W-H)
mm
59 23 30
x
x
g
Weight (approx)
22
Features:Features:
No Min. Load Required
Internal Soft-Start (8ms)
Short-Circuit Robust
No Heatsink Required
AC or DC Input
The best solution with low power dissipation if high input voltage is present,
but your application required a low operating voltage.