IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Features
• RoHS lead-free-solder and lead-solder-exempted
products are available.
• Extremely wide input voltage ranges up to 150 VDC
• 4 outputs up to 60 V
• 1200 to 1800 VAC i/o electric strength test
• Electrical isolation between outputs
• Programmable input undervoltage lockout
63.5
2.5"
• Shutdown/inhibit input
10.5
0.41"
• Adjustable output voltages with flexible load distribution
76.2
3"
• Frequency synchronization
• Outputs no-load, overload, and short-circuit proof
• Operating ambient temperature from – 40 to 85 °C
• Thermal protection
• Low profile: 10.5 mm or 8.9 mm with open frame
• Basic insulation
• Flexible output possibilities between 5 V and 60 V
47.8
1.88"
Safety-approved to IEC/EN 60950 -1 and UL/CSA
60950 -1 2 nd Ed.
8.9
0.35"
72.8
2.87"
Description
The IMX35 Series of board-mountable, 35 Watt DC-DC
converters has been designed according to the latest industry
requirements and standards. The converters are particularly
suitable for use in mobile or stationary applications in
transport, railways, industry, or telecommunication, where
variable input voltages or high transient voltages are
prevalent.
Covering a total input voltage range from 9 V up to 150 V with
4 different models, the converters are available with up to four
electrically isolated outputs from 5 V to 60 V, externally
adjustable and with flexible load distribution. A shutdown input
allows remote converter on/off. Features include consistently
high efficiency over the entire input voltage range, high
reliability, and excellent dynamic response to load and line
changes.
The converters are designed and built according to the
international safety standards IEC/EN/UL 60950, and
Table of Contents
approved by TÜV and CSA. The converters provide basic
insulation.
The circuit is comprised of 2 planar magnetics devices, and all
components are automatically assembled and securly
soldered onto a single PCB without any wire connection.
Magnetic feedback ensures maximum reliability and
repeatability in the control loop over all operating conditions.
Careful considerations of possible thermal stresses ensure
the absence of hot spots providing long life in environments,
where temperature cycles are present. The thermal design
without using any potting material allows operation at full load
up to an ambient temperature of 71 °C in free air and operation
up to 105 °C with airflow. For extremely high vibration
environments the case has holes for screw mounting.
Page
Page
Description ............................................................................. 1
Model Selection ..................................................................... 2
Functional Description ........................................................... 3
Electrical Input Data ............................................................... 4
Electrical Output Data ............................................................ 6
Auxiliary Functions ................................................................. 9
Electromagnetic Compatibility (EMC) .................................. 11
Immunity to Environmental Conditions ................................ 12
Mechanical Data .................................................................. 13
Safety and Installation Instructions ...................................... 14
Options ................................................................................. 15
BCD20009-G Rev AC, 06-May-2013
Page 1 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Model Selection
Table 1: Model Selection
Output 1
Io nom
Vo nom
[V]
[A]
1
2
Output 2
Vo nom
Io nom
[V]
[A]
Output 3
Vo nom
Io nom
[V]
[A]
Output 4
Vo nom
Io nom
[V]
[A]
Input voltage
Vi min to Vi max
[V]
Efficiency 1
ηtyp
ηmin
[%]
[%]
Model
Opt.
i
Z
G
5
5
5
5
1.35
1.4
1.4
1.4
5
5
5
5
1.35
1.4
1.4
1.4
5
5
5
5
1.35
1.4
1.4
1.4
5
5
5
5
1.35
1.4
1.4
1.4
9 to 36
18 to 75
40 to 121
60 to 150 2
82.5
82
83
82
86
87
86
86
20IMX35D05D05-8
40IMX35D05D05-8
70IMX35D05D05-8
110IMX35D05D05-8
12
12
12
12
0.65
0.7
0.7
0.7
12
12
12
12
0.65
0.7
0.7
0.7
12
12
12
12
0.65
0.7
0.7
0.7
12
12
12
12
0.65
0.7
0.7
0.7
9 to 36
18 to 75
40 to 121
60 to 150 2
83.7
83.7
85
84
86
88
88
88
20IMX35D12D12-8
40IMX35D12D12-8
70IMX35D12D12-8
110IMX35D12D12-8
15
15
15
15
0.55
0.6
0.6
0.6
15
15
15
15
0.55
0.6
0.6
0.6
15
15
15
15
0.55
0.6
0.6
0.6
15
15
15
15
0.55
0.6
0.6
0.6
9 to 36
18 to 75
40 to 121
60 to 150 2
85
83.6
84.5
83
88
89
88
88
20IMX35D15D15-8
40IMX35D15D15-8
70IMX35D15D15-8
110IMX35D15D15-8
5
5
5
5
1.35
1.4
1.4
1.4
12
12
12
12
0.65
0.7
0.7
0.7
12
12
12
12
0.65
0.7
0.7
0.7
5
5
5
5
1.35
1.4
1.4
1.4
9 to 36
18 to 75
40 to 121
60 to 150 2
84
84
84
83.6
88
89
88
88
20IMX35D05D12-8
40IMX35D05D12-8
70IMX35D05D12-8
110IMX35D05D12-8
5
5
5
5
1.35
1.4
1.4
1.4
15
15
15
15
0.55
0.6
0.6
0.6
15
15
15
15
0.55
0.6
0.6
0.6
5
5
5
5
1.35
1.4
1.4
1.4
9 to 36
18 to 75
40 to 121
60 to 150 2
83.5
83.5
84
84
88
89
88
88
20IMX35D05D15-8
40IMX35D05D15-8
70IMX35D05D15-8
110IMX35D05D15-8
Efficiency at TA = 25 °C, Vo nom, Io nom
154 V for 2 s.
Part Number Description
40 IMX35 D05 D05 -8 i Z G
Input voltage range Vi
9 to 36 VDC
18 to 75 VDC
40 to 121 VDC
60 to 150 VDC
........................................... 20
........................................... 40
........................................... 70
......................................... 110
Series ....................................................................... IMX35
Outputs 1 and 4 (1st power train) ............... D05, D12, D15
Outputs 2 and 3 (2nd power train) .............. D05, D12, D15
Operating ambient temperature range
TA = – 40 to 85 °C ...................................... - 8
Options:
1
Inhibit ........................................................... -i
Open frame ................................................. Z
RoHS compliant for all six substances ........ G1
G is always placed at the end of the part number.
Preferred for new designs
Product Marking
Converters without option Z are marked with type designation,
input and output voltages and currents, applicable safety
approval and recognition marks, company logo, production
date, and serial no.
BCD20009-G Rev AC, 06-May-2013
Page 2 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Functional Description
The IMX35 converters are comprised of 2 feedback-controlled
interleaved-switching flyback power trains using current mode
PWM (pulse width modulation).
Each converter consists of 4 electrically isolated outputs
deriving from 2 power trains. Vo1, Vo4 derive from the first
power train and Vo2, Vo3 from the second one. Thus each pair
of outputs is independent from the other one.
Voltage regulation for each pair of outputs is achieved with
passive transformer feedback from the main transformer of the
power train. Each pair of outputs has the same output voltage
(i.e. D05, D12, etc.). If both power trains have the same output
voltage (e.g. D12D12), all outputs may be simultaneously
adjusted by the Trim input (pin 5). In case of different output
voltages (e.g. D05D15), the Trim1 input influences only Vo1
and Vo4.
Current limitation is provided by the primary circuit for each
power train and limits the possible output power for each pair
of outputs. In the case of an overload on either of the power
trains, which causes the output voltage to fall less than
typically 60% of Vo nom, the entire converter will shut down and
automatically restart in short intervals (hiccup mode).
The incorporated overtemperature protection shuts down the
converter in excessive overload conditions with automatic
restart.
03098a
Vi+ 4
16 Vo1+
PUL 1
15 Vo1–
Trim/Trim1 5
W 6
PWM
17 Vo4+
Ref 7
SD 8
18 Vo4–
Vi– 2
n.c. 3
13 Vo2+
14 Vo2–
12 Vo3+
11 Vo3–
19 n.c.
Fig. 1
Block diagram of quad-output models
BCD20009-G Rev AC, 06-May-2013
Page 3 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Electrical Input Data
General conditions:
TA = 25 °C, unless specified
Pins 8 (shutdown or i), 6 (W), 5 (Trim or Trim1), and 1 (PUL) left open-circuit (not connected), unless specified.
Table 2: Input Data
Input
20 IMX35
Characteristics
min
92
Nominal input voltage
TA min to TA max
Io = 0 to Io nom
Repetitive surge voltage
Abs. max input (3 s)
t start-up
Converter
Switch on
start-up time 2
S
¯¯
D high
Worst case condition at
Vi min and full load
t rise
Rise time 3
Vi nom resist load
3
Io nom capac. load
6
Ii o
No load input current
Io = 0, Vi min to Vi max
70
50
mA
Iirr
Reflected ripple current
Io = 0 to Io nom
30
30
mApp
Iinr p
Inrush peak current 4
Vi = Vi nom
8
9
A
Ci
Input capacitance
for surge calculation
V ––
Shut down voltage
Converter disabled
Converter operating
approx. 10
approx. 10
Input voltage range 1
Vi nom
Vi sur
SD
R S–D–
Shutdown input resistance
I S–D–
Input current during shutdown Vi
fs
Switching frequency
min
36
18 2
typ
VDC
40
40
0.25
100
0.5
0.25
0.5
0.1
s
0.1
3
12
ms
6
2
12
1.3
µF
–10 to 0.7
–10 to 0.7
V
open circuit or 2 to 20
open circuit or 2 to 20
min to Vi max
12
Vi min to Vi max, Io = 0 to Io nom
220
240
220
70 IMX35
Characteristics
max
75
20
Input
Conditions
min
typ
40 2
Vi
Input voltage range 1
Vi nom
Nominal input voltage
TA min to TA max
Io = 0 to Io nom
Vi sur
Repetitive surge voltage
Abs. max input (3 s)
t start-up
Converter
Switch on
start-up time 2
S
¯¯
D high
Worst case condition at
Vi min and full load
Rise time 3
Vi nom resist load
3
Io nom capac. load
6
t rise
max
Unit
Conditions
Vi
typ
40 IMX35
kΩ
6
mA
240
kHz
110 IMX35
max
min
121
60 2
70
typ
Unit
max
150 5
VDC
110
150
0.25
0.5
170
0.4
0.7
0.1
3
12
s
0.1
ms
6
12
Ii o
No load input current
Io = 0, Vi min to Vi max
30
20
mA
Iirr
Reflected ripple current
Io = 0 to Io nom
30
30
mApp
Iinr p
Inrush peak current 4
Vi = Vi nom
7
7
A
Ci
Input capacitance
for surge calculation
0.5
0.5
µF
VS–D–
Shut down voltage
Converter disabled
–10 to 0.7
–10 to 0.7
V
Converter operating
open circuit or 2 to 20
open circuit or 2 to 20
R S–D–
Shutdown input resistance
approx. 10
approx. 10
I S–D–
Input current during shutdown
Vi
fs
Switching frequency
Vi min to Vi max, Io = 0 to Io nom
1
2
min
to Vi max
Vi min will not be as stated, if Vo is increased above Vo nom by
use of Trim input. If the output voltage is set to a higher value,
Vi min will be proportionately increased.
Input undervoltage lockout at typ. 85% of Vi min.
BCD20009-G Rev AC, 06-May-2013
5
220
3
4
5
240
220
kΩ
5
mA
240
kHz
Measured with resistive and max. admissible capacitive load.
Source impedance according to ETS 300132-2, version 4.3.
154 V during 2 s
Page 4 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Inrush Current
Input Transient Voltage Protection
The inrush current has been kept as low as possible by
choosing a very small input capacitance. A series resistor may
be installed in the input line in order to further reduce this
current.
A built-in suppressor diode provides effective protection
against input transients, which may be generated for example
by short-circuits across the input lines, where the network
inductance may cause high energy pulses.
Table 4: Built-in transient voltage suppressor
A
04022b
4
Model
3
Breakdown
voltage
VBr nom [V]
Peak power
at 1 ms
Ω]
Pp [Ω
Peak pulse
current
I pp [A]
22
2
20IMX35
39
1500
1
40IMX35
100
1500
9.7
70IMX35
151
600
2.9
110IMX35
176
600
2.5
0
20
40
60
80
t
100 µs
Fig. 2
Typical inrush current at Vi nom, Po nom versus time (40IMX35).
Source impedance according to ETS 300132-2 at Vi nom .
Vo
Vo nom
trise
For very high energy transients as for example to achieve
IEC/EN 61000-4-5 compliance (as per table Electromagnetic
Immunity) an external inductor and capacitor are required. The
components should have similar characteristics as listed in
table below.
Table 5: Components for external circuitry for IEC/EN
61000-4-5, level 2
04008b
Model
t
tstartup
Fig. 3
Converter start-up and rise time (see table 2)
Inductor (L)
Capacitor (C)
Diode (D)
20IMX35
22 µH /5 A
470 µF / 40 V
1.5 k E47A
40IMX35
68 µH / 2.7 A
2 x 100 µF /100 V
-
70IMX35
100 µH / 1 A
2 x 82 µF /200 V
-
110IMX35
150 µH /0.8 A
2 x 82 µF / 200 V
-
Reverse Polarity Protection
Vi+
The built-in suppressor diode also provides for reverse
polarity protection at the input by conducting current in the
reverse direction. An external fuse is required to limit this
current.
Table 3: Recommended external fuses in the non-earthed
input line
Converter model
04036a
L
Fuse type
20IMX35
F8.0 A
40IMX35
F4.0A
70IMX35
F2.0A
110IMX35
F1.5A
BCD20009-G Rev AC, 06-May-2013
C
+
D
Vi–
Fig. 4
Example for external circuitry to comply with IEC/EN 610004-5; the diode D is only necessary for 20IMX35 models.
Page 5 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Electrical Output Data
General conditions:
– TA = 25 °C, unless TC is specified
– Pins 8 (shutdown or i), 6 (W), 5 (Trim or Trim1), and 1 (PUL) left open-circuit (not connected), unless specified.
Table 6: Output data per double-output power train (Vo1/Vo4 or Vo2/Vo3; each power train has 2 outputs)
Output
2x5V
Conditions
min
Vo1
Vo2
Output voltage
Vi nom
Io = 0.5 Io nom
4.95
4.94
Io nom
Output current
20IMX Vi min to Vi max
2 × 1.35
2 × 0.65
2 × 0.55
40IMX
2 × 1.4
2 × 0.70
2 × 0.60
Current limit 1
max
min
5.05
5.06
11.88
11.86
typ
2 x 15 V
Characteristics
IoL
typ
2 x 12 V
max
min
12.12
12.14
14.85
14.82
typ
max
15.15
15.18
70IMX
2 × 1.4
2 × 0.70
2 × 0.60
110IMX
2 × 1.4
2 × 0.70
2 × 0.60
3.5
1.8
1.5
3.8
2.0
1.7
20IMX Vi nom, TC = 25 °C
Vo = 93% Vo nom
40IMX
Unit
70IMX
3.8
2.0
1.7
110IMX
3.8
2.0
1.7
A
∆Vo
Line regulation
Vi min to Vi max, Io nom
±1
±1
±1
∆Vo l
Load regulation
Vi nom
I o = (0.1 to 1) Io nom
±3
±3
±3
Vo1/2
Output voltage noise
Vi min to Vi max
I o = Io nom
2
80
120
150
3
40
60
70
limit. 4
Vo L
Output overvoltage
Co ext
Admissible capacitive load
per power train 5
produced after 2011
Vo d
Dynamic
load
regulation
Vi nom
Io nom ↔ 1/2 Io nom
±250
Vi min to Vi max
I o = (0.1 to 1) Io nom
td
αVo
1
2
3
4
5
Voltage deviat.
Recovery time
Temperature coefficient
∆Vo /∆T C
Min. load 1%
VDC
%
mVpp
115
130
115
130
115
130
%
0
6000
0
680
0
470
µF
± 480
±520
mV
0.75
0.75
0.75
ms
±0.02
±0.02
±0.02
%/K
Both outputs of each power train connected in parallel. The current limit is primary side controlled. In the event of a sustained overload
condition, the thermal protection may cause the converter to shut down (restart on cool-down).
BW = 20 MHz, measured with an external capacitor of 1 µF across the output pins.
Measured with a probe according to EN 61204
The overvoltage protection is via a primary side second regulation loop, not tracking with Trim control.
Sum of the capacities on both outputs of each power train
BCD20009-G Rev AC, 06-May-2013
Page 6 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Thermal Considerations
Vo [%]
If a converter, mounted on a PCB, is located in free, quasistationary air (convection cooling) at the indicated maximum
ambient temperature TA max (see table Temperature specifications) and is operated at its nominal input voltage and output
power, the case temperature TC (TC Z with option Z) measured
at the measuring point of case temperature (see Mechanical
Data) will approach the indicated value TC max after the warmup phase. However, the relationship between TA and TC
depends heavily on the conditions of operation and integration
into a system. The thermal conditions are influenced by input
voltage, output current, airflow, temperature of surrounding
components and the surfaces and properties of the printed
circuit board. TA max is therefore only an indicative value, and
under practical operating conditions, the ambient temperature
TA may be higher or lower than this value.
Caution: The case temperature TC (or TC Z) measured at the
measuring point of case temperature (see Mechanical Data) may
under no circumstances exceed the specified maximum value.
The installer must ensure that under all operating conditions TC (or
TC Z) remains within the limits stated in the table Temperature
specifications.
The converters provide the specified output power with free air
convection cooling. In the upper temperature range the output
power derating below should be observed.
Po /Po max
overload short-circuit condition
100
switch-off
05041b
70
0
0.3 s
t
Fig. 6
Overload switch off (hiccup mode), typical values.
Series and Parallel Connection
The outputs of one or several double-output power trains may
be connected in series respecting the current limitation.
Both outputs of the same power train can always be
connected in parallel in will behave like a single output.
Several outputs of the same converter with equal output
voltage (e.g. 5 V / 5 V) can be connected in parallel and will
share their output currents almost equally.
If outputs of the same converter are being parallel and seriesconnected, it is recommended that outputs from the same
power trains are parallel-connected first. This applies for
instance, if 24 V shall be generated by a converter with four
12 V outputs; see fig. 7.
11047-X35a
1.0
JM138
IMX35D12D12-9
0.8
Vi+ 4
0.5 m/s = 100 LFM
16
Vo1+
0.6
PUL 1
natural cooling
0.4
W
0.2
0
15
Trim 5
6
PWM
17
Vo1–
Vo4+
Ref 7
20
40
60
80
100
°C
TA
Fig. 5
SD 8
18
Vo4–
–24V
Vo2+
+24V
Vi– 2
n.c. 3
Maximum allowed output power versus ambient
temperature.
13
14
12
Vo2–
Vo3+
Overtemperature Protection
The converter is protected against possible overheating by
means of an internal temperature monitoring circuit. It shuts
down the converter above the internal temperature limit and
attempts to automatically restart. This feature prevents
excessive internal temperature building up which could occur
under heavy overload conditions.
Short Circuit Behavior
The current limit characteristic shuts down the converter
whenever a short circuit is applied to an output. It acts selfprotecting and automatically recovers after removal of the
overload condition (hiccup mode).
BCD20009-G Rev AC, 06-May-2013
11
Vo3–
19 n.c.
Fig. 7
Generating 24 V with an IMX35D12D12-9
Note: Parallel operation of several converters may cause startup problems. This becomes noticable in applications, where one
converter is not able to deliver allone the full resistive and
capacitive load current, as it is required in true redundant systems.
Page 7 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
η [%]
Typical Performance Curves
90
General conditions:
– TA = 25°C, unless TC is specified.
– Shut down and Trim pin left open-circuit.
05153a
Vi min
80
Vo [V]
Vi nom
05020-X35
13
70
12
11
60
25
10
9
50
75
Po
100 % Po total
Fig. 11
8
0
0.5
1.5
1
2
A
Io total
Efficiency versus input voltage and load. Typical values
(20IMX35D12D12-8)
Fig. 8
Vo versus Io (typ.) of double-output power trains, with both
outputs in parallel (e.g., Vo1/4 of a 40IMX35D12D12)
η [%]
90
05152a
Vi min
Vi nom
Vo4 [V]
80
05164b
13.5
13
12.5
12
Io4 = 0.035 A
70
Io4 = 0.35 A
60
25
11.5
Io1
0.06 0.1
0.2
0.3
0.4
0.5
0.6
0.7 A
50
75
Po
100 % Po total
Fig. 12
Efficiency versus input voltage and load. Typical values
(40IMX35D12D12-8)
Fig. 9
Cross load regulation (typ.) on power train 1. Vo4 versus Io1
Vo1, Vo4 [V]
05039b
14
13
Vo4
12
Vo1
11
10
0
0.25
0.5
0.75
1
1.25
1.5
Io1/Io1 nom
Fig. 10
Flexible load distribution (typ.) on power train 1 of a
40IMX35D12D12-8:
Vo1 versus Io1, Io4 = 0.5 Io4 nom
BCD20009-G Rev AC, 06-May-2013
Page 8 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Auxiliary Functions
Table 8: Vo versus Vext for Vo = 85 to 105% Vo nom;
typical values (Vi nom, Io = 0.5 Io nom)
Adjustable Output Voltage
Vo [% Vo nom]
As a standard feature, the IMX35 offer adjustable output
voltages in the range of 85 to 105% of Vo nom. Fig. 12 shows the
schematic diagram for the adjustment of quad-output models.
>105
102
100
95
90
85
All models with equal output voltages have a Trim input at pin
5 referenced to the primary side, influencing all outputs simultaneously. Models with different output voltages exhibit a
Trim1 input, influencing only the first power train (Vo1 and Vo4).
Vext [V]
Trim [V]
Trim1 [V]
0
1.8
2.5
4.3
6.2
8
0
1.5
2.5
4.25
6.2
8
Adjustment by means of an external resistor Rext:
Synchronization (W)
06137c
Vi+
Trim
4
16
5
15
+
Vext
–
Control
circuit
Vref = 2.5 V
Rext
Vi–
13
2
14
Vo1+
Vo1–
Vo2+
Vo2–
Fig. 13
Adjustment of the output voltage by means of an external
resistor Rext is possible within the range of 100 to 105% of
Vo nom. Rext should be connected between Trim (pin 5) and Vi–
(pin 2). The following table indicates suitable resistor values for
typical output voltages under nominal conditions (Vi nom, Io =
0.5 Io nom).
Note: Connection of Rext to Vi+ may damage the converter.
Adjustment by means of an external voltage source Vext
Table 7: Rext for Vo > Vo nom;
approximate values (Vi nom, Io = 0.5 Io nom)
Ω]
Rext [kΩ
Tr i m
Trim1
0
10
62
0
17
110
105 to 108 (107 typically)
105
102
100
∞
This logic input W can be used to synchronize the oscillator to
an external frequency source. This signal is edge-triggered
with TTL thresholds and requires a source frequency of 490 to
540 kHz (duty cycle 10 to 90%). The external source frequency
is internally divided by 2 to define the switching frequency of
the converter. If unused, this pin can be connected to V1– (pin
2) or left open-circuit.
Reference Output (Ref)
Output voltage control by means of the Trim input
Vo [% Vo nom]
It is possible to synchronize the switching frequency of one or
more converters to an external clock signal.
The converter provides a stable 5 V (±0.1 V) reference signal
on pin 7 (Ref). The output is protected by a 1 kΩ resistor. The
signal may be used also in conjunction with the Trim input (pin
5) as a limited external voltage reference.
It is recommended to connect a filter capacitor (0 .1 µF)
between Ref and Vi–, if Ref is used.
Shutdown
The outputs of the converters may be enabled or disabled by
means of a logic signal (TTL, CMOS, etc.) applied to shutdown (pin 8). If the shutdown function is not required, pin 8
should be left open-circuit:
Converter operating:
2.0 to 20 V
Converter disabled:
–10 to 0 .7 V
∞
For external output voltage adjustment in the range 85 to
105% of Vo nom a voltage source Vext (0 to 20 V) is required,
connected to Trim or Trim1 (pin 5) and Vi–. The table below
indicates typical values Vo versus Vext. Applying a control
voltage of 15 to 20 V will set the converter into the hiccup
mode. Direct paralleling of the Trim pins of converters of the
same type connected in parallel is feasible.
BCD20009-G Rev AC, 06-May-2013
Page 9 of 15
IMX35 Series Data Sheet
35 Watt Quad-Output DC-DC Converters
®
Progr. Input Undervoltage Lockout PUL
A special feature of the converters (with Rev. BA or later) is the
adjustable undervoltage lockout protection, which protects
the converter (and the system) from high current caused by
operation at low input voltages. This ensures easier start-up
in distributed power systems.
The table below shows the band of switch on/off and the
hysteresis.
Table 9: Trigger level and hysteresis (pin 1 left open)
Model
Trigger level
Hysteresis
Unit
20IMX35
7 to 8