Capacitive Load
Delivery Package Information
The PKF series has no maximum limit for capacitive load on the
output. The power module may operate in current limiting mode
during start-up, affecting the ramp-up and the start-up time. For
optimum start performance we recommend maximum 100 mF/A
of IO. Connect capacitors at the point of load for best perfor-
mance.
Tubes
The PKF-series is delivered in tubes (designated by /A) with a
length of 500 mm (19.69 in), see fig. 5.
Parallel Operation
Paralleling of several converters is easily accomplished by direct
connection of the output voltage terminal pins. The load regula-
tion characteristic is specifically designed for optimal paralleling
performance. Load sharing between converters will be within
10%. It is recommended not to exceed PO = n × 0.9 × PO
,
max
where POmax is the maximum converter output power and n the
number of paralleled converters, to prevent overloading any of the
converters and thereby decreasing the reliability performance.
Figure 5
Specification
Current Limiting Protection (Ilim
The output power is limited at loads above the output current
limiting threshold (Ilim), specified as a minimum value.
)
Material:
Antistatic coated PVC
Max surface resistance: 1011W/
Color:
Transparent
10 power modules/tube
Typ. 60 g
Capacity:
Weight:
End stops:
Pins
Synchronization (Sync)
It is possible to synchronize the switching frequency to an
external symmetrical clock signal. The input is TTL-compatible
and referenced to the input pin 18.
Trays
SMD versions, SI, can be delivered in standard JEDEC trays
(designated by /B) on request, see fig. 6. For more information,
please contact your local Ericsson sales office.
Characteristics
min
typ
max
unit
High level
2.2
1.2
0
6.5
2.2
0.4
1.5
688
V
V
Threshold level*)
Low level
1.7
V
Sink current
Sync. frequency
mA
kHz
520
*) Rise time <10ns
Input and Output Impedance
Both the source impedance of the power feeding and the load im-
pedance will interact with the impedance of the DC/DC power
module.
It is most important to have the ratio between L and C as low
as possible, i.e. a low characteristic impedance, both at the input
and output, as the power modules have a low energy storage
capability.
Use an electrolytic capacitor across the input if the source
inductance is larger than 10 mH. Their equivalent series resist-
ance together with the capacitance acts as a lossless damping fil-
ter. Suitable capacitor values are in the range 10–100 mF.
Figure 6
Specification
Material:
Max temperature:
Max surface resistance: 105W/
Polypropylene (PP)
125ºC
Color:
Black
14
EN/LZT 146 31 R1A (Replaces EN/LZT 137 21 R6) © Ericsson Microelectronics AB, June 2000
ERICSSON [ ERICSSON ]
