40IMX35D12D12-8

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 • 1500 to 1800 VAC i/o electric strength test • Electrical isolation between outputs • Programmable input undervoltage lockout 10.5 0.41" 63.5 2.5" • Shutdown/inhibit input 76.2 3" • Adjustable output voltages with flexible load distribution • 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" 8.9 0.35" Safety-approved to IEC/EN 60950 -1 and UL/CSA 60950 -1 2 nd Ed. 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 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 Copyright © 2015, Bel Power Solutions Inc. All rights reserved. MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. Page 1 of 15 IMX35 Series Data Sheet 35 Watt Quad-Output DC-DC Converters Model Selection Table 1: Model Selection Output 1 Vo nom Io nom [V] [A] 1 2 Output 2 Output 3 Output 4 Input voltage Efficiency 1 ηmin Vo nom Io nom Vo nom Io nom Vo nom Io nom Vi min to Vi max [V] [A] [V] [A] [V] [A] [V] [%] Model ηtyp [%] Opt. 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 84.5 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 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 84 83.5 84 84 86 89 88 88 20IMX35D05D15-8 40IMX35D05D15-8 70IMX35D05D15-8 110IMX35D05D15-8 i Z G 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: Inhibit ........................................................... -i Open frame .................................................. Z RoHS compliant for all six substances ......... G Note: The sequence of options must follow the order above ! 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. MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. 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 powertrains 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 powertrain 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 powertrain. Each pair of outputs has the same output voltage (i.e. D05, D12, etc.). If both powertrains 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 powertrain 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 overtemperature conditions with automatic restart. 03098a Vi+ 4 16 Vo1+ PUL 1 15 Vo1– Trim/Trim1 5 W 6 17 Vo4+ PWM Ref 7 18 Vo4– SD 8 Vi– 2 n.c. 3 13 Vo2+ 14 Vo2– 12 Vo3+ 11 Vo3– 19 n.c. Fig. 1 Block diagram of quad-output models MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. 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 20IMX35 Characteristics Conditions min 92 typ 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 40 IMX35 max min 36 18 2 Unit typ max 75 20 VDC 40 40 0.25 100 0.5 0.25 0.5 0.1 s 0.1 3 12 ms 6 12 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 2 1.3 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 –– Inputcurrentduring shutdown Vi fs Switching frequency Vi min to Vi max, Io = 0 to Io nom SD min to Vi max 12 220 Input 1 Conditions min 40 2 Vi Input voltage range 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 t rise 240 220 70 IMX35 Characteristics Rise time 3 kΩ typ 6 mA 240 kHz 110 IMX35 max min 121 60 2 70 typ 150 5 150 0.5 170 0.4 0.7 0.1 3 Io nom capac. load 6 VDC 110 0.25 Vi nom resist load Unit max s 0.1 3 12 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 Ci Input capacitance for surge calculation VS–D– Shut down voltage R S–D– Shutdown input resistance I –– Inputcurrentduring shutdown Vi fs Switching frequency Vi min to Vi max, Io = 0 to Io nom SD 1 2 7 7 A 0.5 0.5 µF 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 approx. 10 approx. 10 min to Vi max 5 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. 220 3 4 5 6 240 kΩ 5 225 mA 6 kHz Measured with resistive and max. admissible capacitive load. Source impedance according to ETS 300132-2, version 4.3. 154 V during 2 s Revision B A or later. Older converters had fs ≤ 240 kHz. MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. 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 shortcircuits across the input lines, where the network inductance may cause high energy pulses. Table 4: Built-in transient voltage suppressor A 04022b Model 4 Breakdown voltage VBr nom [V] 3 Peak power at 1 ms Ω] Pp [Ω Peak pulse current I pp [A] 2 20IMX35 39 1500 22 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 04008b 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 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 04036a L 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. C + D Vi– Table 3: Recommended external fuses in the non-earthed input line Converter model Fuse type 20IMX35 F8.0A 40IMX35 F4.0A 70IMX35 F2.0A 110IMX35 F1.5A Fig. 4 Example for external circuitry to comply with IEC/EN 610004-5; the diode D is only necessary for 20IMX35 models. MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. 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 powertrain (Vo1/Vo4 or Vo2/Vo3; each power train has 2 outputs) Output 2x5V Characteristics Conditions min Vo1 Vo2 Output voltage Vi nom Io = 0.5 Io nom 4.95 4.94 Io nom Output current IoL typ 2 x 12 V max min 5.05 5.06 11.88 11.86 typ 2 x 15 V max min 12.12 12.14 14.85 14.82 typ max 15.15 15.18 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 70IMX 2 × 1.4 2 × 0.70 2 × 0.60 110IMX 2 × 1.4 2 × 0.70 2 × 0.60 Current limit 1 Unit 20IMX Vi nom, TC = 25 °C Vo = 93% Vo nom 40IMX 3.5 1.8 1.5 3.8 2.0 1.7 70IMX 3.8 2.0 1.7 110IMX 3.8 2.0 A 1.7 ∆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 5 Vi min to Vi max I o = Io nom 2 80 120 150 3 40 60 70 4 Vo L Output overvoltage limit Co ext Admissible capacitive load per power train 6 produced after 2011 produced until 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 6 Voltage deviat. Recovery time Temperature coefficient ∆Vo /∆TC Min. load 1% VDC % mVpp 115 130 115 130 115 130 % 0 0 6000 4000 0 0 680 470 0 0 470 330 µF ±480 ±520 mV 0.75 0.75 0.75 ms ±0.02 ±0.02 ±0.02 %/K Both outputs of each powertrain 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 µ F 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. Both outputs of each powertrain connected in parallel. Sum of capacities on the outputs of each control powertrain. MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. Page 6 of 15 IMX35 Series Data Sheet 35 Watt Quad-Output DC-DC Converters Vo [%] Thermal Considerations 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 powertrains may be connected in series respecting the current limitation. Both outputs of the same powertrain 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 powertrains 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 SD 8 18 Vo4– –24V Vo2+ +24V Vi– 2 n.c. 3 Fig. 5 Maximum allowed output power versus ambient temperature (models without option Z) 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). 11 Vo3– 19 n.c. Fig. 7 Generating 24 V with an IMX35D12D12-9 Note: Parallel operation of several converters may cause start-up problems. This becomes noticable in applications, where one converter is not able to deliver alone the full resistive and capacitive load current, as it is required in true redundant systems. MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. 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 50 75 Po 100 % Po total 9 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 powertrain 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 MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. 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– 2 13 14 It is possible to synchronize the switching frequency of one or more converters to an external clock signal. Vo1+ Vo1– 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. Vo2+ Vo2– Fig. 13 Reference Output (Ref) Output voltage control by means of the Trim input 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. 105 to 108 (107 typically) 105 102 100 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: Table 7: Rext for Vo > Vo nom; approximate values (Vi nom, Io = 0.5 Io nom) Ω] Rext [kΩ Vo [% Vo nom] 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. Trim Trim1 0 10 62 0 17 110 ∞ ∞ Converter operating: 2.0 to 20 V Converter disabled: –10 to 0 .7 V Adjustment by means of an external voltage source Vext 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. MELCHER BCD20009-G Rev AD, 10-Aug-2015 The Power Partners. 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