PKR2000A Datasheet, PDF (19/27 Pages) Ericsson – DC/DC converters, Input 18-36 V, Output up to 2 A/15 W

E
Ericsson Internal
PRODUCT SPECIFICATION
Prepared (also subject responsible if other)
No.
ESKEVIN
3/1301-BMR 640_T1_e2_c1_h1+_niU_ce_an_{l Specification}
Approved
S^PE^KC^R/D²(⁰J⁰ul⁰ia^AYo^su^e)^ries
Checked
EZYPING
Date
2007-8-20
Rev
Reference
E_BN/LZT 146 352 R2C September 2007
DC/DC converters, Input 18-36 V, Output up to 2 A/15 W ^{© Ericsson Power Modules AB}
Operating information continued
Thermal Consideration
3 (5)
19
Parallel Operation
Paralleling of several converters is easily accomplished by
direct connection of the output voltage terminal pins. The
load regulation characteristic is specifically designed for
optimal paralleling performance. Load sharing between
converters will be within ±10%. It is recommended not to
exceed
P_O = n x 0.9 x P_Omax, where P_Omax is the maximum
converter output power and n is the number of paralleled
converters, to prevent overloading any of the converters and
thereby decreasing the reliability performance.
Over Temperature Protection (OTP)
The PKR 2000A Series DC/DC converters include an internal
over temperature shutdown circuit.
When the temperature exceeds 130°C - 150°C on the control
circuit the converter will shut down. The DC/DC converter will
make continuous attempts to start up (non-latching mode)
and resume normal operation automatically when the
temperature has dropped >15°C below the temperature
threshold.
Over Current Protection (OCP)
The converters include current limiting circuitry for protection
at continuous overload.
The output voltage will decrease towards zero for output
currents in excess of max output current (max I_O). The
converter will resume normal operation after removal of the
overload. The load distribution should be designed for the
maximum output short circuit current specified.
Synchronization
It is possible to synchronize the switching frequency to an
external symmetrical clock signal. The input can be driven by
a TTL-compatible output and reference to the -input pin 18.
General
The converters are designed to operate in different thermal
environments and sufficient cooling must be provided to
ensure reliable operation.
Cooling is achieved mainly by conduction, from the pins to
the PCB board, and convection, which is dependant on the
airflow across the converter. Increased airflow enhances the
cooling of the converter.
The Output Current Derating graph found in the Output
section for each model provides the available output current
vs. ambient air temperature and air velocity at V_in = 27 V.
The converter is tested on a 254 x 254 mm,
35 μm (1 oz), 8-layer test board mounted vertically in a wind
tunnel with a cross-section of 305 x 305 mm.
Proper cooling of the converter can be verified by measuring
the temperature at position P1. The temperature at these
positions should not exceed the max values provided in the
table below.
Note that the max value is the absolute maximum rating
(non destruction) and that the electrical Output data is
guaranteed up to T_ref +95°C.
See Design Note 019 for further information.
Position
P₁
P₂
P₃
Device
Transformer
Mosfet
PCB
Designation
T_ref
max value
110º C
P₁
Characteristic
Min
Typ Max Unit
High level
2.2
6.5
V
Threshold level*)
1.2
1.7 2.2
V
Low level
0
0.4
V
Sink current
Sync. Frequency 520
1.5
mA
668
kHz
*) Rise time < 10ns
Air Flow