SRAH-05B / VRAH-05B Series RoHS Compliant Nonisolated Compact, low profile surface mount package Fixed frequency High efficiency means less power dissipation Excellent thermal performance Optimized for cost Remote on/off Undervoltage lockout UVLO) Over current and short circuit protection Description The Bel SRAH-05B and VRAH-05B modules are a series of non-isolated, step down DC/DC power converters that operate from a nominal 5V source. These converters are available in a range of output voltages from to. They are packaged in a compact, overmolded package rated at 5A. Optional lead forming provides a vertical mount product for minimal footprint or a surface mount option for a very low profile. Standard features include remote on/off, over current and short circuit protection, and output voltage adjust. These products may be used almost anywhere low voltage silicon is employed and a 5V source is available. Typical applications include file servers, routers, line cards and other computing and communications equipment. Applications Distributed power architectures Data networking equipment Telecommunications Computers and peripherals Part Number Selection Voltage Input Voltage Max. Current Max. Power Typical Efficiency Part Number Surface Mount Part Number Vertical Mount 5V 5A 16.5W 92% SRAH-05B0 VRAH-05B0 5V 5A 12.5W 90% SRAH-05B0 VRAH-05B0 5V 5A 9.0W 86% SRAH-05B VRAH-05B 5V 5A 7.5W 84% SRAH-05B VRAH-05B 5V 5A 6 W 82% SRAH-05B120 VRAH-05B120 page 1
Absolute Maximum Ratings Parameter Symbol Min Typical Max Unit Continuous Input Voltage Enable Terminal Voltage Ambient Temperature Storage Temperature Vin -0. 6 V Vouten -0. 6 V Tamb 0 70 C tor -40 C Note: Use beyond the maximum ratings may cause a reliability degradation of the DC/DC converter or may permanently damage the device. Input Specifications Parameter Module Symbol Min Typical Max Units Operating Input Voltage Vin 4. 5 5. 5 V Input Current Iin 4.6.6 2.7 2. 1.9 A No Load Input Current 0 ma Remote Off Input Current 4 8 ma 1 Input Reflected Ripple Current 0 60 ma rms 1 Input Reflected Ripple Current P-P) mapk I 2 t Inrush Current Transient 0.02 0.05 A 2 s Turn On Voltage Threshold Turn Off Voltage Threshold 4.19 4. 4. 5 V. 9 4.49 V Note: Input capacitance one µf/16v, ESR = 0.018 Ω max at khz @ C. 1. With simulated source impedance of 0nH, 5Hz to 20MHz. page 2
Specifications Parameter Module Symbol Min Typical Max Units 1 Voltage Set Point Vout.24 2.45 1.764 1.47 1.176. 2.5 1.8 1.5 1.2.66 2.55 1.86 1.5 1.224 V Load Regulation 6.0 6.0 6.0 6.0 6.0 15 15 15 15 15 Line Regulation.0.0.0.0.0 10 10 8 8 8 Regulation Over Temperature 20 20 10 10 8 18 15 12 Total Voltage Regulation 58 41 8 5 2 Ripple and Noise p-p 2 Ripple and Noise 15 rms Current Range DC Current Limit Iout 0 5 A Ioutlim 6. 5 12. 5 A Short Circuit Surge Ioutsurge 0.08 0.05 0.05 0.05 0.05 0.2 0.1 0.1 0.1 0.1 A 2 s Turn on Ton 12 20 ms Overshoot at Turn On 0 % Capacitance Cout 0 2000 µ F Note: specifications are typical at nominal input, full load at C unless otherwise stated. 1. Vin = 5V, Iout = full load, Ta = C. 2. 0-20MHz, 1µF ceramic cap and 10µF aluminum cap on output. page
Specifications Parameter Module Symbol Min Typical Max Units Transient Response V % to % of Max Load 120 165 V % to % of Max Load 120 165 Transient Response V % to % of Max Load V % to % of Max Load Transient Response V % to % of Max Load V % to % of Max Load Transient Response V % to % of Max Load V % to % of Max Load Transient Response V % to % of Max Load V % to % of Max Load Note: specifications are typical at nominal input, full load at C unless otherwise stated.. di/dt = 0.5A/1µS, Ta = C without external load capacitance. page 4
General Specifications Parameter Module Symbol Min Typical Max Units 1 Efficiency η 89 87 8 81 79 92 90 86 84 82 % Switching Frequency Fsw 260 00 40 khz 2 Voltage Trim Range 90 110 % Weight 4. 7 g 1. Vin=5V, full load and Ta= C. 2. See graphs on pages 10-12. Control Specifications Parameter Module Symbol Min Typical Max Units Remote On/Off Vouten V Signal Low Unit On) Signal High Unit Off) 0 1 V 2. 8 5. 5 V. With remote on/off pin 1 open, the module is on. page 5
Efficiency Data Module Module Efficiency 97% 96% 95% 94% 9% 92% 1 2 4 5 6 Current 4.5V 5.0V 5.5V Efficiency 95% 94% 9% 92% 91% 90% 1 2 4 5 6 Current 4.5V 5.0V 5.5V Efficiency 9% 92% 91% 90% 89% 88% 87% 86% Module 1 2 4 5 6 Current 4.5V 5.0V 5.5V Efficiency 92% 91% 90% 89% 88% 87% 86% 85% Module 1 2 4 5 6 Current 4.5V 5.0V 5.5V Efficiency 88% 87% 86% 85% 84% 8% 82% 81% Module 1 2 4 5 6 Current 4.5V 5.0V 5.5V page 6
Ripple and Noise 1µF ceramic cap and 10µF aluminum electrolytic cap added at the output. Ripple and noise at full load and 5Vdc input, dc output and Ta= C Ripple and noise at full load and 5Vdc input, dc output and Ta= C Ripple and noise at full load and 5Vdc input, dc output and Ta= C Ripple and noise at full load and 5Vdc input, dc output and Ta= C Ripple and noise at full load and 5Vdc input, dc output and Ta= C page 7
Transient Response Transient response: di/dt = 0.5A/µS, no external load capacitance Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C page 8
Transient Response Transient response: di/dt = 0.5A/µS, no external load capacitance Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C Vout= % to % load transients at 5V input and Ta= C page 9
Thermal Considerations SRAH-05B VRAH-05B page 10
Voltage Set-Point Adjustment Trim Down Test Circuit Trim Up Test Circuit Vo Vo Trim Trim Gnd Gnd Voltage Set-Point Adjustment xrah-05b0 Trim Resistor Calculation Rtrim down = 7.914 Vo Vo, adj 8.27) Kohm Trim resistor value Rtrim_downKohm). 01 120. 01 0.01 0. 01 2.97.04.07.1.1.17.2.2.27. Adjusted output voltage Vo,adj V) Rtrim up = 2.528 Vo, adj Vo 5.11) Kohm Trim resistor value,rtrim_upkohm). 01 120. 01 0.01 0. 01...7.4.4.46.5.5.56.6.6 Adjusted output voltage Vo,adjV) page 11
Voltage Set-Point Adjustment xrah-05b0 Trim Resistor Calculation Rtrim down =.664 Vo Vo, adj 6.79) Kohm Trim resistor value Rtrim_downKohm).01 120.01 0.01 0.01 2. 2.27 2. 2. 2.5 2.8 2.4 2.42 2.45 2.48 2.5 Adjusted output voltage Vo,adj V) Rtrim up = 1.72 Vo, adj Vo 4.64) Kohm Trim resistor value,rtrim_upkohm).01 120.01 0.01 0.01 2.5 2.52 2.55 2.58 2.6 2.6 2.65 2.67 2.7 2.7 2.75 Adjusted output voltage Vo,adjV) Trim resistor value Rtrim_downKohm) 00.1.2..4.5 120.6 90.7 60.8 0.9 1 1.62 1.64 1.66 1.67 1.69 1.71 1.7 1.75 1.76 1.78 1.8 Adjusted output voltage Vo,adj V) xrah-05b Trim Resistor Calculation Rtrim down = 1.9 Vo Vo, adj 5.52) Kohm 00 Trim resistor value,rtrim_upkohm).1.2..4.5 120.6 90.7 60.8 0.9 Rtrim up = 1.2 Vo, adj Vo 4.02) Kohm 1 1.8 1.82 1.8 1.85 1.86 1.88 1.9 1.91 1.9 1.94 1.96 Adjusted output voltage Vo,adjV) page 12
Voltage Set-Point Adjustment xrah-05b Trim Resistor Calculation Rtrim down = 2.702 Vo Vo, adj 11.7) Kohm Trim resistor value Rtrim_downKohm).01 120.01 0.01 0.01 1.5 1.7 1.8 1.4 1.41 1.4 1.44 1.46 1.47 1.49 1.5 Adjusted output voltage Vo,adj V) Rtrim up =.064 Vo, adj Vo 7.87) Kohm Trim resistor value,rtrim_upkohm).01 120.01 0.01 0.01 1.5 1.51 1.5 1.54 1.56 1.58 1.59 1.61 1.62 1.64 1.65 Adjusted output voltage Vo,adjV) Trim resistor value Rtrim_downKohm).01 120.01 0.01 0.01 1.08 1.09 1.1 1.12 1.1 1.14 1.15 1.16 1.18 1.19 1.2 Adjusted output voltage Vo,adj V) xrah-05b120 Trim Resistor Calculation Rtrim down = 1.545 Vo Vo, adj 8.47) Kohm Trim resistor value,rtrim_upkohm).01 120.01 0.01 Rtrim up =.064 Vo, adj Vo 4.64) Kohm 0.01 1.2 1.21 1.22 1.24 1. 1.26 1.27 1.28 1. 1.1 1.2 Adjusted output voltage Vo,adjV) page 1
Mechanical SRAH-05B 0.400 [10.16] Suggested PCB Pad Layout 0.065 [1.65] 0.60 [15.24] 0.0 [1.27] 0.855 [21.72] 0.110 [2.79] 0.70 [17.78] 0. [2.54] R0.015 [R0.8] typ R0.008 [R0.20] typ 0.012 [0.0] 0-5 0.0 0.20 [1.27] 0. [8.1] 0.020 [2.54] [0.51] 0.400 4x [10.16] 0.780 [19.81] 0.004 [0.10] 0.055 [1.40] 2x 0.090 [2.29] 2x Dimensions are in inches [millimeters]. Standard dimension tolerance is ±0.005 [0.1] unless otherwise noted. Pin Function 7 6 1 Remote On/Off 2 +Vin Ground 4 +Vo 5 Trim 6 No Connection 7 No Connection 1 2 4 5 page 14
Mechanical VRAH-05B 0.700 [17.78] 0.600 [15.24] 0.0 [1.27] 0.265 [6.7] min 0.0 [1.27] 0. [2.54] 0.400 [10.16] 0.020 [0.51] 0.08 [7.82] Dimensions are in inches [millimeters]. Standard dimension tolerance is ±0.005 [0.1] unless otherwise noted. Pin Function 1 Remote On/Off 2 +Vin Ground 4 +Vo 5 Trim 1 2 4 5 RoHS Compliance Complies with the European Directive 2002/95/EC, calling for the elimination of lead and other hazardous substances from electronic products. These parts are not however compatible with the higher temperatures associated with lead free solder processes and must be soldered using a reflow profile with a peak temperature of no more than ºC. CORPORATE Bel Fuse Inc. 206 Van Vorst Street Jersey City, NJ 0702 Tel 201-42-046 Fax 201-42-9542 www.belfuse.com FAR EAST Bel Fuse Ltd. 8F / 8 Luk Hop Street San Po Kong Kowloon, Hong Kong Tel 852-228-5515 Fax 852-2-706 www.belfuse.com EUROPE Bel Fuse Europe Ltd. Preston Technology Management Centre Marsh Lane, Suite G7, Preston Lancashire, PR1 8UD, U.K. Tel 44-1772-556601 Fax 44-1772-88866 www.belfuse.com page 15