The resistance is given by the following equation
(For VIon>37 V):
Operating Information
R
Ion = 100× (100.2 – VIon)/(VIon – 36.5) kW
Fuse Considerations
where 36.5 is the typical unadjusted turn-on input voltage (V).
To prevent excessive current from flowing through the input supply
line, in the case of a short-circuit across the converter input, an exter-
nal fuse should be installed in the non-earthed input supply line. We
recommend using a fuse rated at approximately 2 to 4 times the value
calculated in the formula below:
VIoff is the adjusted turn-off input voltage and is determined by
VIon –VIoff = 2 V (typical value).
To decrease VIon a resistor should be connected between pin 10 and
11 (see fig. 3). The resistance is given by the following equation (for
30 V < VIon > 36 V:
PO
max
Iin
=
max
(hmin × VImin)
RIon = 364 × (VIon – 29.9)/(36.5 – VIon) kW
Refer to the fuse manufacturer for further information.
Decrease V
Increase V
Remote Control (RC)
Ion
Ion
TOA (pin 10)
−In (pin 17)
Turn-on or turn-off can be realized by using the RC-pin. Normal
operation is achieved if pin 11 is open (NC). If pin 11 is connected to
pin 17 the power module turns off. To ensure safe turn-off the voltage
difference between pin 11 and 17 shall be less than 1.0 V. RC is TTL
open collector compatible output with a sink capacity >100 mA (see
fig. 1).
RIon
RIon
RC (pin 11)
RC (pin 11)
Figure 3
Output Voltage Adjust (Vadj
)
Output voltage, VO, can be adjusted by using an external resistor.
Typical adjust range is 15%. If pins 8 and 9 are not connected to-
gether the output will decrease to a low value. To increase VO a resis-
tor should be connected between pin 8/9 and 18, and to decrease VO a
resistor should be connected between pin 8 and 9 (see fig. 4).
Figure 1
Over Voltage Protection (OVP)
Typical required resistor value to increase VO is given by:
Radj = k1 × (k2 – VO)/(VO – VOi) kW
The remote control can be utilized also for OVP by using the exter-
nal circuitry in figure 2. Resistor values are for 5 V output applica-
tions, but can easily be adjusted for other output voltages and the
desired OVP level.
where VO is the desired output voltage,
VOi is the typical output voltage initial setting
andk
1=0.684
k1=0.495
k1=0.495
k1=0.566
k1=0.495
k1=0.495
k1=0.495
k1=0.566
k2= 2.46 V
k2= 3.93 V
k2= 5.87 V
k2=15.00 V
k2= 5.87V
k2= 3.93 V
k2= 5.87 V
k2=15.00 V
PKF 4310
PKF 4510
PKF 4611
PKF 4621*)
PKF 4622
PKF 4628
PKF 4629
PKF 4713*)
Out 1 (pin 1)
15k
1.2k
1k
TL431
270
RC (pin 11)
10k
Typical required resistor value to decrease VO is given by:
adj = k1 × (VOi – VO)/(VO – k2) kW
R
Rtn (pin 2)
ꢀIn (pin 17)
where k1=2.751
k1=1.986
k2=1.75 V
k2=2.59 V
k2=4.12 V
k2=9.52 V
k2=4.12 V
k2=2.59 V
k2=4.12 V
k2=9.52 V
PKF 4310
PKF 4510
PKF 4611
PKF 4621
PKF 4622
PKF 4628
PKF 4629
PKF 4713
Figure 2
k1=1.986
k1=2.284
k1=1.986
k1=1.986
k1=1.986
k1=2.284
Turn-on/off Input Voltage
The power module monitors the input voltage and will turn on and
turn off at predetermined levels set by means of external resistors.
*)
Over 13.8V output voltage, the input voltage range is
limited to 38...65V.
To increase VIon a resistor should be connected between pin 11 and
17 (see fig. 3).
EN/LZT 146 33 R1A (Replaces EN/LZT 137 09 R7) © Ericsson Microelectronics AB, June 2000
19
ERICSSON [ ERICSSON ]
