ISOLATED DC-DC CONVERTER CEB75 SERIES APPLICATION NOTE

ISOLATED DC-DC CONVERTER CEB75 SERIES APPLICATION NOTE Approved By: Department Approved By Checked By Written By Enoch Louis Joyce Research and Development Department Danny Quality Assurance Department Jack Benny 1

Contents 1. Introduction... 3 2. DC-DC Converter Features... 3 3. Electrical Block Diagram... 3 4. Technical Specifications... 5 5. Main Features and Functions... 7 5.1 Operating Temperature Range...7 5.2 Output Voltage Adjustment...7 5.3 Over Current Protection...7 5.4 Output Overvoltage Protection...7 5.6 Remote ON/OFF...7 5.7 UVLO (Undervoltage Lock Out)...7 5.8 Over Temperature Protection...7 6. Applications... 7 6.1 Recommended Layout, PCB Footprint and Soldering Information...7 6.2 Convection Requirements for Cooling...8 6.3 Thermal Considerations...8 6.4 Power Derating...8 6.6 Efficiency VS. Load:...9 6.7 Test Set-Up...10 6.8 Output Voltage Adjustment...10 6.9 Output Remote Sensing...11 6.10 Output Ripple and Noise...11 6.11 Output Capacitance...11 7. Safety & EMC... 12 7.1 Input Fusing and Safety Considerations...12 7.2 EMC Considerations...12 8. Part Number... 13 9. Mechanical Specifications... 13 9.1 Mechanical Outline Diagrams...13 2

1. Introduction This specification describes the features and functions of Cincon s CEB75 series of isolated DC-DC Converters. These are highly efficient, reliable and compact, high power density, single output DC/DC converters. The modules can be used in the field of telecommunications, data communications, wireless communications, servers etc. The CEB75 series can deliver up to 25A output current and provide a precisely regulated output voltage over a wide range of input voltages (Vi =36-75Vdc). The modules can achieve high efficiency up to 92%. The module offers direct cooling of dissipative components for excellent thermal performance. Standard features include remote On/Off, remote sense, output voltage adjustment, over voltage, over current and over temperature protection. The CEB75 series also have the following options: remote On/Off (positive or negative). 2. DC-DC Converter Features 62-84W Isolated Output Efficiency (at full load) up to 92% Regulated Output Input Under Voltage Protection Over Current Protection Over Temperature Protection Remote ON/OFF Control Eighth Brick Package 1500VDC Isolation Safety Meets UL60950-1 3. Electrical Block Diagram +VIN +Vout -Vout OVP -VIN ON/OFF CONTROL REMOTE SWITCH CONTROL UVLO OTP COMPARATORS PWM CONTROLLER OPTO ISOLATION REFERENCE & ERROR AMP +SENSE -SENSE TRIM Electrical Block Diagram for 2.5Vout, 3.3Vout and 5.0Vout modules 3

+VIN +Vout -Vout -VIN OVP ON/OFF CONTROL REMOTE PWM CONTROLLER OPTO ISOLATION REFERENCE & ERROR AMP +SENSE -SENSE TRIM UVLO OCP OTP Electrical Block Diagram for 12Vout module 4

4. Technical Specifications (All specifications are typical at nominal input, full load at 25 C unless otherwise noted.) ABSOLUTE MAXIMUM RATINGS PARAMETER NOTES and CONDITIONS Device Min. Typical Max. Units Input Voltage Continuous All 36 48 75 V dc Transient 100ms All 100 V dc Operating Temperature A -40 85 C Storage Temperature All -40 125 C Isolation Voltage 1 minute; input/output, input/case, output/case All 1500 V dc INPUT CHARACTERISTICS Operating Input Voltage All 36 48 75 V dc Input Undervoltage Lockout Turn-On Voltage Threshold All 35 V dc Turn-Off Voltage Threshold All 33 V dc Lockout Hysteresis Voltage All 2 V dc Maximum Input Current 100% Load, V in=36v All 2.6 A Vo=2.5 V dc 60 No-Load Input Current Vo=3.3 V dc 60 ma Vo=5.0 V dc 50 Vo=12 V dc 70 Inrush Current (I 2 t) All 1 A 2 s Input Reflected Ripple Current P-P thru 12uH inductor, 5Hz to 20MHz All 30 ma OUTPUT CHARACTERISTICS PARAMETER NOTES and CONDITIONS Device Min. Typical Max. Units Vo=2.5 V dc 2.475 2.5 2.525 Output Voltage Set Point V in=nominal V in, I o = I o_max, Tc=25 C Vo=3.3 V dc 3.267 3.3 3.333 Vo=5.0 V dc 4.95 5 5.05 Vo=12 V dc 11.88 12 12.12 Output Voltage Regulation Load Regulation I o=i o_min to I o_max All ±0.5 % Line Regulation V in=low line to high line All ±0.2 % Temperature Coefficient TC=-40 C to 100 C All ±0.03 %/ C Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth Peak-to-Peak Full load, 10uF tantalum and 1.0uF ceramic capacitors All 100 mv Vo=2.5 V dc 0 25 Operating Output Current Range Vo=3.3 V dc 0 20 A Vo=5.0 V dc 0 15 Vo=12 V dc 0 7 Output DC Current Limit Inception Output Voltage=90% Nominal Output Voltage All 110 135 160 % Vo=2.5 V dc 10000 V dc Maximum Output Capacitance Full load (resistive) Vo=3.3 V dc 10000 Vo=5.0 V dc 10000 μf Vo=12 V dc 1500 5

DYNAMIC CHARACTERISTICS PARAMETER NOTES and CONDITIONS Device Min. Typical Max. Units Output Voltage Current Transient Step Change in Output Current 75% to 100% of I o_max All ±5 % Setting Time (within 1% Vout nominal) d i/d t=0.1a/us All 400 us Turn-On Delay and Rise Time Turn-On Delay Time, From On/Off Control V on/off to 10%V o_set Vo=2.5 V dc Vo=3.3 V dc Vo=5.0 V dc 10 ms Vo=12 V dc 3 Turn-On Delay Time, From Input V in_ min to 10%V o_set Vo=2.5 V dc Vo=3.3 V dc Vo=5.0 V dc 100 ms Vo=12 V dc 15 Output Voltage Rise Time 10%V o_set to 90% Vo_set All 5 ms EFFICIENCY Vo=2.5 V dc 89 100% Load ISOLATION CHARACTERISTICS Vo=3.3 V dc 90 Vo=5.0 V dc 90 Vo=12 V dc 92 % Isolation Voltage 1 minute; input/output, input/case, output/case All 1500 V dc Isolation Resistance All 10 MΩ Isolation Capacitance All 1000 pf FEATURE CHARACTERISTICS PARAMETER NOTES and CONDITIONS Device Min. Typical Max. Units Switching Frequency ON/OFF Control, Positive Remote On/Off logic Vo=2.5 V dc Vo=3.3 V dc 250 Vo=5.0 V dc 200 Vo=12 V dc 350 KHz Logic Low (Module Off) V on/off All 1.2 V Logic High (Module On) V on/off All ON/OFF Control, Negative Remote On/Off logic Logic High (Module Off) V on/off All 6 Open Circuit 3.5 or Open Circuit 15 V 15 V Logic Low (Module On) V on/off All 1.2 V ON/OFF Current (for both remote on/off logic) I on/off at V on/off=0.0v 1 ma Leakage Current (for both remote on/off logic) Logic High, V on/off=15v 30 ua Off Converter Input Current Shutdown input idle current 20 ma Output Voltage Trim Range P out=max rated power -10 +10 % Output Over Voltage Protection 115 130 140 % Over-Temperature Shutdown 120 C GENERAL SPECIFICATIONS MTBF I o=100% of I o_max; T a=25 C per MIL-HDBK-217F TBD Weight 26 grams M hours

5. Main Features and Functions 5.1 Operating Temperature Range The CEB75 series converters can be operated within a wide Ambient temperature range of -40 C to 85 C. Consideration must be given to the derating curves when ascertaining maximum power that can be drawn from the converter. The maximum power drawn from eighth brick m odels is inf luenc ed b y usual factors, such as: Input voltage range Output load current Forced air or natural convection 5.2 Output Voltage Adjustment Section 6.8 describes in detail how to trim the output voltage with respect to its set point. The output voltage on all models is adjustable within the range of +10% to 10%. 5.3 Over Current Protection The converter is protected against over current or short circuit conditions. At the instance of current-limit inception, the module enters a hiccup mode of operation, whereby it shuts down and automatically attempts to restart. While the fault condition exists, the module will remain in this hiccup mode, and can remain in this mode until the fault is cleared. The unit operates normally once the output current is reduced back into its specified range. 5.4 Output Overvoltage Protection The output overvoltage protection consists of circuitry that internally limits the output voltage. If more accurate output over voltage protection is required then an external circuit can be used via the remote on/off pin. 5.6 Remote ON/OFF The CEB75 series allows the user to switch the module on and off electronically with the remote on/off feature. All models are available in positive logic and negative logic (optional) versions. The converter turns on if the remote ON/OFF pin is high (open circuit). Setting the pin low (<1.2Vdc) will turn the converter off. The signal level of the remote on/off input is defined with respect to ground. If not using the remote on/off pin, leave the pin open (converter will be on). Models with part number suffix N are the negative logic remote ON/OFF version. The unit turns off if the remote ON/OFF pin is high (open circuit). The converter turns on if the ON/OFF pin input is low (<1.2Vdc). Note that the converter is off by default. 5.7 UVLO (Undervoltage Lock Out) Input under voltage lockout is standard on the CEB75 unit. The unit will shut down when the input voltage drops below a threshold, and the unit will operate when the input voltage goes above the upper threshold. 5.8 Over Temperature Protection These modules have an over temperature protection circuit to safeguard against thermal damage. A temperature sensor monitors the temperature of the hot spot (typically, top switch). If the temperature exceeds a threshold of 120 C (typical) the converter will shut down, disabling the output. When the temperature has decreased the converter will automatically restart. The over-temperature condition can be induced by a variety of reasons such as external overload condition or a system fan failure. 6. Applications 6.1 Recommended Layout, PCB Footprint and Soldering Information The system designer or end user must ensure that metal and other components in the vicinity of the converter meet the spacing requirements for which the system is approved. Low resistance and inductance PCB layout traces are the norm and should be used where possible. Due consideration must also be given to proper low impedance tracks between power module, input and output grounds. The recommended soldering profile and PCB layout are shown below. Temperature ( C) Lead Free Wave Soldering Profile 300 250 200 150 100 50 0 0 50 100 150 Time (Seconds) Note: 1. Soldering Materials: Sn/Cu/Ni 2. Ramp up rate during preheat: 1.4 /Sec ( From 50 to 100 ) 3. Soaking temperature: 0.5 /Sec ( From 100 to 130 ), 60±20 seconds 4. Peak temperature: 260, above 250 3~6 Seconds 5. Ramp up rate during cooling: -10.0 /Sec ( From 260 to 150 ) 7

Iout(A) 6.2 Convection Requirements for Cooling To predict the approximate cooling needed for the Quarter brick module, refer to the power derating curves in section 6.4. These derating curves are 6.4 Power Derating Curve approximations of the ambient temperatures and airflows required to keep the power module temperature below its maximum rating. 6.3 Thermal Considerations The power module operates in a variety of thermal environments; however, sufficient cooling should be provided to help ensure reliable operation of the unit. Heat is removed by conduction, convection, and radiation to the surrounding environment. The power output of the module should not be allowed to exceed rated power (V o_set x I o_max ).. The operating ambient temperature range of CEB75 series is -40 to + 85. When operating the CEB75 series, proper derating or cooling is needed. 25 23 21 19 17 15 13 11 20LFM 100LFM 200LFM 300LFM CEB75-48S2V5 Derating Curve 25 30 35 40 45 50 55 60 65 70 75 80 Ta( o C) Iout(A) 20 18 16 14 12 10 8 6 20LFM 100LFM 200LFM 300LFM CEB75-48S3V3 Derating Curve 25 30 35 40 45 50 55 60 65 70 75 80 Ta( o C) Iout(A) 15 13 11 9 7 5 20LFM 100LFM 200LFM 300LFM CEB75-48S05 Derating Curve 25 30 35 40 45 50 55 60 65 70 75 80 Ta( o C) Output Load(A) 7 6 5 4 3 2 1 0 20LFM 100LFM 200LFM 300LFM CEB75-48S12 Derating Curve 25 30 35 40 45 50 55 60 65 70 75 80 Ta( o C) 8

6.6 Efficiency VS. Load: Efficiency (%) CEB75-48S2V5 (Eff Vs Io) 100% 90% 80% 36V 70% 48V 60% 75V 50% 40% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Current Load (%) Efficiency (%) 100% 90% 80% 70% CEB75-48S3V3 (Eff Vs Io) 36V 48V 75V 60% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100 Current Load (%) % 100% CEB75-48S05 (Eff Vs Io) 100% CEB75-48S12 (Eff Vs Io) Efficiency (%) 90% 80% 70% 60% 36V 48V 75V 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Current Load (%) Efficiency (%) 90% 80% 70% 36V 48V 60% 75V 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Current Load (%) 9

6.7 Test Set-Up The basic test set-up to measure parameters such as efficiency and load regulation is shown below. When testing the modules under any transient conditions please ensure that the transient response of the source is sufficient to power the equipment under test. We can calculate: Efficiency Load regulation and line regulation. The value of efficiency is defined as: Vo Io η = 100% Vin Iin Where: V o is output voltage, I o is output current, V in is input voltage, I in is input current. The value of load regulation is defined as: VFL VNL Load. reg = 100% VNL Where: V FL is the output voltage at full load V NL is the output voltage at no load The value of line regulation is defined as: VHL VLL Line. reg = 100% VLL Where: V HL is the output voltage of maximum input voltage at full load. V LL is the output voltage of minimum input voltage at full load. + Vin - A C1 V +Vin -Vin +Vo +Sense Trim -Sense -Vo CEB75 Series Test Setup 6.8 Output Voltage Adjustment In order to trim the voltage up or down one needs to connect the trim resistor either between the trim pin and -Vo for trim-up and between trim pin and +Vo for trim-down. The output voltage trim range is ±10%. This is shown in Figures 1 and 2: V A Load +Vin -Vin +Vout +SENSE Trim -SENSE -Vout Figure 1. Trim-up Voltage Setup +Vin -Vin +Vout +Sense Trim -Sense -Vout Figure 2. Trim-down Voltage Setup 1. The value of Rtrim_up defined as: R trim-up R-Load R-Load R trim-down For output voltage 2.5V to 5.0V 5.11 Vo, set (100 + %) 511 Rtrim _ up = 10.22 1.225 % % R For output voltage12v trim _ up 5.1 Vo, set (100 + %) 510 = 10.2 1.225 % % For example, to trim-up the output voltage of 12V module (CEB75-48S12) by 8% to 12.96V, R trim_up is calculated as follows: (KΩ) (KΩ) 5.1 12 (100 + 8) 510 Rtrim _ up = 10.2 = 600.50 (KΩ) 1.225 8 8 2. The value of R trim_down defined as: R trim For output voltage 2.5V to 5.0V _ down Where: 511 = 10.22 % (KΩ) Vo, set Vdesired % = 100 Vo, set 10

R trim For output voltage12v _ down Where: 510 = 10.2 % (KΩ) Vo, set Vdesired % = 100 Vo, set For example, to trim-down the output voltage of 12V module (CEB75-48S12) by 8% to 11.04V, R trim-down is calculated as follows: R trim _ down 510 = 10.2 = 53.55 8 6.9 Output Remote Sensing (KΩ) The CEB75 SERIES converter has the capability to remotely sense both lines of its output. This feature moves the effective output voltage regulation point from the output of the unit to the point of connection of the remote sense pins. This feature automatically adjusts the real output voltage of the CEB75 SERIES in order to compensate for voltage drops in distribution and maintain a regulated voltage at the point of load. The remote-sense voltage range is: [(+Vout) - (-Vout)] [(+Sense) (-Sense)] 10% of Vo_nominal If the remote sense feature is not to be used, the sense pins should be connected locally. The +Sense pin should be connected to the +Vout pin at the module and the -Sense pin should be connected to the -Vout pin at the module. This is shown in the schematic below. Vin + - C1 +Vin +Vout +Sense Trim Rwire R-Load Note: Although the output voltage can be varied (increased or decreased) by both remote sense and trim, the maximum variation for the output voltage is the larger of the two values not the sum of the values. The output power delivered by the module is defined as the voltage at the output terminals multiplied by the output current. Using remote sense and trim can c a u s e t h e o u t p u t v o l t a g e t o i n c r e a s e a n d consequently increase the power output of the module if output current remains unchanged. Always ensure that the output power of the module remains at or below the maximum rated power. Also be aware that if V o.set is below nominal value, P out.max will also decrease accordingly because I o.max is an absolute limit. Thus, P out.max = V o.set x I o.max is also an absolute limit. 6.10 Output Ripple and Noise V in +V +V o in +Sense Load + Resistor Trim - 1uF 10uF BNC -Sense To Scope -V in -V o Output ripple and noise is measured with 1.0uF ceramic and 10uF solid tantalum capacitors across the output. 6.11 Output Capacitance The CEB75 series converters provide unconditional stability with or without external capacitors. For good transient response, low ESR output capacitors should be located close to the point of load. PCB design emphasizes low resistance and inductance tracks in consideration of high current applications. Output capacitors with their associated ESR values have an impact on loop stability and bandwidth. These series converters are designed to work with load capacitance to see technical specifications. -Vin -Sense -Vout Rwire 11

7. Safety & EMC 7.1 Input Fusing and Safety Considerations The CEB75 series converters have no internal fuse. In order to achieve maximum safety and system protection, always use an input line fuse. We recommended a 3A time delay fuse for the 48Vin models. It is recommended that the circuit have a transient voltage suppressor diode (TVS) across the input terminal to protect the unit against surge or spike voltage and input reverse voltage (as shown). FUSE +Vin +Vo + Vin - TVS R-Load -Vin -Vo 7.2 EMC Considerations EMI Test standard: EN55022 Class B Conducted Emission Test Condition: Input Voltage: Nominal, Output Load: Full Load +Vin L1 L2 +Vout C1 C5 C2 C3 CEB75-48S12 R1 -Vin C4 -Vout Figure 3 Connection circuit for conducted EMI testing Model No. C1 C2 C3 C4 C5 L1 L2 CEB75-48S12 4.7uF/100V 4.7uF/100V 33uF/100V 1000pF/3KV 1000pF/3KV 1.3mH 3.4mH Note: The C1 and C2, C4, C5 are ceramic capacitors, C3 is aluminum capacitors. 12

8. Part Number Format: CEB75 II X OO L Parameter Series Nominal Input Voltage Number of Outputs Output Voltage Remote ON/OFF Logic Symbol CEB75 II X OO L 2V5: 2.5 Volts Value CEB75 48: 48 Volts 9. Mechanical Specifications 9.1 Mechanical Outline Diagrams S: Single 3V3: 3.3 Volts 05: 05 Volts 12: 12 Volts None: N: Positive Negative 2.30 (58.4) 2.000 (50.80) 0.90 (22.9) 0.600 (15.24) 0.106 (2.70) 0.040 (1.02) 0.300 (7.62) 0.600 (15.24) 0.39 (10.0 ) 0.145 (3.68) 0.062 (1.57) CINCON ELECTRONICS CO., LTD. Headquarters: 14F, No.306, Sec.4, Hsin Yi Rd. Taipei, Taiwan Tel: 886-2-27086210 Fax: 886-2-27029852 E-mail: sales@cincon.com.tw Web Site: http://www.cincon.com Factory: No. 8-1, Fu Kung Rd. Fu Hsing Industrial Park Fu Hsing Hsiang, Chang Hua Hsien, Taiwan Tel: 886-4-7690261 Fax: 886-4-7698031 Cincon North America: 1655 Mesa Verde Ave. Ste 180 Ventura, CA 93003 Tel: 805-639-3350 Fax: 805-639-4101 E-mail: info@cincon.com 13