To increase VIon a resistor should be connected between pin 11
and 18 (see fig. 3).
Operating Information
Fuse Considerations
The resistance is given by the following equation
(For VIon>18.4V):
To prevent excessive current from flowing through the input
supply line, in the case of a short-circuit across the converter in-
put, an external 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:
R
Ion = (k1 – VIon)/(VIon – k2) kW
where k2 is the typical unadjusted turn-on input voltage (V).
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 17.0V < VIon >18.3V:
PO
max
Iin
=
max
RIon = k3 × (VIon – k4)/(k2 – VIon) kW
(hmin × VImin
)
k1
k2
k3
k4
1020
1020
1020
18.3
18.4
18.4
22
27
25
16.9
17.0
17.0
PKF 2111A, PKF 2113A
PKF 2610A
PKF 2611
Refer to the fuse manufacturer for further information.
Remote Control (RC)
Turn-off level. VIoff is the adjusted turn-off level and is deter-
mined by the following equation: VIoff = VIon – 1.5V (typical
value).
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 con-
nected to pin 18 the power module turns off. To ensure safe turn-
off the voltage difference between pin 11 and 18 shall be less than
1.0V. RC is an TTL open collector compatible output with a sink
capacity >300 mA (see fig. 1).
Decrease V
Increase V
Ion
Ion
TOA (pin 10)
−In (pin 18)
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 pin 8 and 9 is not connected to-
gether the output will decrease to a low value. To increase VO a
resistor 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)
The remote control can be utilized also for OVP by using the ex-
ternal circuitry in figure 2. Resistor values are for 5V output app-
lications, but can easily be adjusted for other output voltages and
the desired OVP level.
Typical required resistor value to increase VO is given by:
R
adj = k5 × (k6 – VO)/(VO – VOi) kW
where VO is the desired output voltage,
Oi is the typical output voltage initial setting
V
Out 1 (pin 1)
and
k5= 4.2
k5= 4.2
k6= 6.27 V
k6= 15.0 V
PKF 2111A
PKF 2113A
15k
1.2k
1k
k5= 3.18
k5= 3.18
k6= 3.90V
k6= 5.85V
PKF 2610A
PKF 2611
TL431
Typical required resistor value to decrease VO is given by:
adj = k7 × (VOi – VO)/(VO – k8) kW
270
RC (pin 11)
10k
R
where k7= 18.0
k7= 18.6
k8= 2.76 V
k8= 6.50 V
k8= 1.70 V
k8= 4.28 V
PKF 2111A
PKF 2113A
PKF 2610A
PKF 2611
k7= 17.2
k7= 12.5
Rtn (pin 2)
-In (pin 18)
Figure 2
Increase VO
Decrease VO
–In (pin 18)
V
adj
(pin 8)
Turn-on/off Input Voltage
The power module monitors the input voltage and will turn on
and off at predetermined levels. The typical turn-on level (with-
out any external resistor) is 18.4 V and the typical turn-off level is
17.0 V, a slight deviation can occur due to tolerances in the
manufacturing process. These levels can be adjusted by means of
external resistors.
Radj
Radj
NOR (pin 9)
Vadj, NOR (pin 8, 9)
Figure 4
EN/LZT 146 31 R1A (Replaces EN/LZT 137 21 R6) © Ericsson Microelectronics AB, June 2000
13
ERICSSON [ ERICSSON ]
