WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module 7 - 50V / 2.5A / 2.5 - 15V Output DESCRIPTION FEATURES The VDRM series of the MagI³C Power Module family provide a fully integrated DC-DC power supply including the buck switching regulator and inductor in a package. The WPMDU1251501 offers high efficiency and delivers up to 2.5A of output current. It operates from 7V input voltage up to 50V. It is designed for fast transient response.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module VOUT 13 12 VOUT VOUT 12 29 INTSS 27 EN/UVLO 28 SS/TRK 26 VIN 25 BOOT 24 SW 23 SW 22 SW 21 SW VOUT 39 33 AGND 34 AGND SW 38 35 PG 36 FB RSET INT 1 13 VOUT 20 PGND 19 PGND VOUT 14 COMP 2 VOUT 11 VOUT 10 NC 9 NC 8 SW 7 SW 6 AGND 5 AGND 4 COMP 2 RCCOMP 3 RSET INT 1 FB 6 14 VOUT 32 AGND AGND 37 RCCOMP 3 PG 35 VOUT 15 AGND 4 VOUT 39 SW 38 15 VOUT 31 RT/CLK Bottom view AGND 5 AGND
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module PINS FOR OPTIONAL USE SYMBOL PIN TYPE PIN DESCRIPTION EN/UVLO 27 Input Enable and UVLO adjust pin. Use an open drain or open collector logic device to ground this pin to disable the device. A resistor divider between this pin, AGND, and VIN sets the UVLO voltage. RT/CLK 31 Input This pin sets the switching frequency. Left open will set the internal oscillator to the default switching frequency.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module ORDERING INFORMATION ORDER CODE 171021501 178021501 PART DESCRIPTION WPMDU1251501NT Evaluation Board SPECIFICATIONS 2.5A / 37.5W version 2.5A / 37.5W version PACKAGE BQFN-41 PACKING UNIT Tape and Reel with 250 Units 1 PACKAGE SPECIFICATIONS Weight Molding compound UL class Certificate number 0.54g EME-G770H UL94 V-0 E41429 SALES INFORMATION SALES CONTACTS Würth Elektronik eiSos GmbH & Co.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module ABSOLUTE MAXIMUM RATINGS Caution: Exceeding the listed absolute maximum ratings may affect the device negatively and may cause permanent damage. VIN VOUT AGND SW EN/UVLO FB PG SS/TRK INTSS RT/CLK Tstorage TSOLR Mechanical Shock Mechanical Vibration LIMITS PARAMETER SYMBOL MIN -0.3 -0.6 -0.2 -0.6 -2 -0.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module ELECTRICAL SPECIFICATIONS MIN and MAX limits are valid for the recommended ambient temperature range of -40°C to 85°C. Typical values represent statistically the utmost probability at following conditions: VIN = 24 V, VOUT = 5.0 V, IOUT = 2.5 A, RT = Open, CIN = 2 x 2.2 μF ceramic, COUT = 2 x 47 μF ceramic, unless otherwise specified. SYMBOL PARAMETER TEST CONDITIONS MIN (1) TYP (2) MAX (1) UNIT - 5.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module PARAMETER SYMBOL TEST CONDITIONS Transient response Recovery time Transient response VOUT over/undershoot TTR VTR IQ Input quiescent current MIN (1) TYP (2) MAX (1) UNIT - 400 - µs - 90 - mV 1.3 4 µA Transient Response 1A/µs load step from 50 to 100%, 1A/µs load step from 50 to 100%, Quiescent current EN = 0V, TA = 25°C, 3.5V ≤ VIN ≤ 60V Non switching: VFB = 0.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module TYPICAL PERFORMANCE CURVES If not otherwise specified, the following conditions apply: VIN = 7-50V; CIN = 2x 2.2µF X7R ceramic; CO = 2x 47µF X7R ceramic, TAMB = 25°C. Thermal Derating: VIN = 12V; VOUT = all voltages Thermal Derating: VIN = 24V; VOUT = all voltages 90 Ambient Temperature [°C] Ambient Temperature [°C] 90 80 70 60 50 40 30 Natural Convection 20 0 0.5 1.0 1.5 2.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module TYPICAL PERFORMANCE CURVES If not otherwise specified, the following conditions apply: VIN = 7-50V; CIN = 2x 2.2µF X7R ceramic; CO = 2x 47µF X7R ceramic, TAMB = 25°C.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module TYPICAL PERFORMANCE CURVES If not otherwise specified, the following conditions apply: VIN = 7-50V; CIN = 2x 2.2µF X7R ceramic; CO = 2x 47µF X7R ceramic, TAMB = 25°C. Efficiency: VIN = 12V @ TAMB = 25°C Power Loss: VIN = 12V @ TAMB = 25°C 100 6 VOUT = 5.0V, fSW =500 kHz VOUT = 3.3V, fSW =400 kHz VOUT = 2.5V, fSW =400 kHz 95 5 Power Loss [W] Efficiency [%] 90 85 80 75 70 65 VOUT = 5.0V, fSW = 500 kHz VOUT = 3.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module TYPICAL PERFORMANCE CURVES If not otherwise specified, the following conditions apply: VIN = 7-50V; CIN = 2x 2.2µF X7R ceramic; CO = 2x 47µF X7R ceramic, TAMB = 25°C. Efficiency: VIN = 48V @ TAMB = 25°C Power Loss: VIN = 48V @ TAMB = 25°C 6 100 VOUT = 15V, fSW = 1000 kHz VOUT = 12V, fSW = 800 kHz VOUT = 5.0V, fSW = 500 kHz VOUT = 3.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module BLOCK DIAGRAM 6, 7, 21-24, 38, 41 Linear Regulator SW BOO T 25 Power Module Cboot 4.9µH 26 VIN VIN CIN VIN UVLO RSET PWM Controller Driver Protection Circuitry EN/UVLO PGND 27 VOUT 10-15, 39 Error Amplifier VOUT COUT FB 36 0.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module DESIGN FLOW The next 10 simple steps will show how to select the external components to design your power application. Essential Steps 1. 2. 3. 4. Set output voltage Set operating frequency Select input capacitor Select output capacitor Optional Steps 5. 6. 7. 8. 9. 10.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module For other output voltages the value of RSET can be calculated using the following formula. VOUT R SET = 10 ∗ ( − 1) kΩ 0.798 (1) The MagI³C Power Module operates over the input voltage range of 7 V to 50 V. For reliable start-up and operation at light loads, the minimum input voltage depends on the output voltage (see table below).
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module It is also possible to synchronize the switching frequency to an external clock signal. See the Step 8.Synchronization CLK option section for further details. While it is possible to set the operating frequency higher than 400 kHz when using the device at output voltages of 5 V or less, minimum duty cycle and pulse skipping issues restrict the maximum recommended input voltage under these conditions.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Step 3 Select input capacitor (CIN) The WPMDU1251501 MagI³C power module contains no internal input capacitors. Therefore an external input capacitance placed directly at the VIN pin is required to handle the input ripple current of the application. The input capacitor can be several capacitors in parallel.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Step 4 Select output capacitor (COUT) L HS Mosfet IL Iout VCOUT VIN COUT CIN VOUT LS Mosfet VES R Rload ESR None of the required output capacitors is integrated within the module. . At a minimum, the output capacitor must meet the worst case RMS current rating of 0.5 ∗ ∆𝐼𝐿 , as calculated in equation (4).
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module The use of very low ESR capacitors leads to an output voltage ripple as shown below: Output voltage ripple with low ESR capacitors Output voltage ripple [mV] 10 5 0 -5 -10 0 1 2 3 time [µs] When capacitors with slightly higher ESR are utilized, the dominant parameter which influences the output voltage ripple is just the ESR: ESR ≤ VOUT ripple ∆IL (7) Consequently the shape of the output voltage ripple ch
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Selection by load step requirements The output voltage is also affected by load transient (see picture below). By the output current transition from a low to a high value, the voltage at the output capacitor (VOUT) drops. This involves two contributions. One is caused by the voltage drop across the ESR (V ESR) and depends on the slope of the rising edge of the current step (trise).
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module In order to choose the value of the output capacitor, the following steps should be followed: 1. 2. 3. According to the operating conditions (VIN, VOUT and fSW), select the minimum COUT recommended in table on page 38. Measure td. Calculate the appropriate value of COUT for the maximum voltage drop Vdischarge allowed at a defined load step, using the following equation (10), derived from equation (9): COUT ≥ 4.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module The result with three MLCC of 47µF in parallel is shown below: Load transient with C OUT = 2x47µF MLCC + 220µF electrolytic 4 0,30 IOUT 3 0,20 0,10 1 IOUT [A] 24µs 0 ΔVOUT = 0.16V Vdischarge = 0.1V -1 0,00 VOUT -0,10 -2 VOUT (AC coupled) [V] 2 -0,20 -3 -4 -0,30 0 20 40 60 80 100 120 time [µs] In order to have a safer margin from the desired ΔVOUT<0.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Step 5 Select Soft-Start capacitor (CSS) Programmable soft-start permits the regulator to slowly ramp up to its steady state operating point after being enabled, thereby reducing current inrush from the input supply and slowing the output voltage rise-time to prevent overshoot. 26 VIN 35 27 CIN 31 VIN PG RSET Module FB EN/UVLO RT/CLK PGND VOUT VOUT 36 COUT AGND INTSS 29 SS/TRK 28 Figure 2.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module For output voltages of 5 V or less, the soft-start capacitance built into the MagI³C Power Module is sufficient for a turn-on ramp rate that does not induce large surge currents while charging the output capacitors. For output voltages higher than 5 V, an additional soft-start capacitance is recommended.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Step 6 Optional: Program undervoltage lockout divider (RUVLO1 and RUVLO2) The function of the RUVLO1 and RUVLO2 divider is to allow the designer to choose an input voltage below which the circuit will be disabled. This implements the feature of programmable external undervoltage lockout. This is often used in battery powered systems to prevent deep discharge of the system battery.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module The VON UVLO threshold must be set to at least (VOUT + 3 V) or 6.5 V whichever is higher to insure proper startup and reduce current surges on the host input supply as the voltage rises. If possible, it is recommended to set the UVLO threshold to approximately 80% to 85% of the minimum expected input voltage. VOFF should be selected to be at least 500 mV less than VON.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Step 7 Optional: Enable / Disable The EN pin provides electrical on/off control of the device. Once the EN pin voltage exceeds the threshold voltage, the device starts operation. If the EN pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low quiescent current state. Figure 7 shows the typical application of the enable function.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Step 8 Optional: Voltage tracking In some applications where a digital IC with 2 or more V CC pins are supplied by the power modules the simultaneous voltage rise on those pins during start up might be required (see Figure 11). Typical examples are, power supply of most FPGAs, DSPs, or other microprocessors.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module VON Enable threshold VEN 0 t VOUT VOUT1 VOUT2 0 t t0 t1 t2 Figure 11. Simultaneous voltage tracking waveforms First select R2TR . A value below 10K is recommended. Use equation 8 to calculate the resistor R1 TR. VOUT2 R1TR = ( − 1) ∗ R2TR 0.8 (12) For proper operation the following condition must be assured: VOUT2 < 0.8 ∗ VOUT1 we-online.com (13) Würth Elektronik eiSos GmbH & Co.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Step 9 Optional: Synchronization to an external clock An internal phase locked loop (PLL) allows synchronization between 300 kHz and 1 MHz, and to easily switch from RT mode to CLK mode. To implement the synchronization feature, connect a square wave clock signal to the RT/CLK pin with a duty cycle between 20 % to 80 %. The clock signal amplitude must transition lower than 0.8 V and higher than 2.0 V.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Light Load Operation The MagI³C Power Module is a non-synchronous converter. One of its characteristics is, that as the load current on the output is decreased a point is reached where the energy delivered by a single switching pulse is more than the load can absorb. This causes the output voltage to rise slightly.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module PCB Layout Instructions: PC board layout is an important part of DC-DC converter design. Poor board layout can disrupt the performance of a DCDC converter and surrounding circuitry by contributing to EMI, ground bounce and resistive voltage drop in the traces. These can send erroneous signals to the DC-DC converter resulting in poor regulation or instability.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module The placement of the input capacitors is highlighted in the following picture of the reference board: CSS EN/UVLO RUVLO2 SS/TRK RUVLO1 CIN2 CIN1 CIN3 VIN INTSS PGND AGND RT/CLK SW COUT1 COUT2 RRT PG VOUT FB RSET 2: Have a single point ground The ground connections for the clock setting, soft-start, and enable components should be routed to the AGND pin of the device.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module 3: Minimize trace length to high impedance pins The feedback resistor, RSET should be located close to the FB pin. Since the FB node is high impedance, maintain the copper area as small as possible. The traces from RSET should be routed away from the body of the MagI³C power module to minimize noise pickup. Place RRT, and CSS as close as possible to their respective pins.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module 5: Provide adequate device heat-sinking Place a dedicated AGND copper area beneath the MagI³C Power Module. CSS EN/UVLO RUVLO2 SS/TRK RUVLO1 CIN2 CIN1 CIN3 VIN INTSS PGND AGND RT/CLK SW COUT1 COUT2 RRT PG VOUT FB RSET Use an array of heat-sinking vias to connect the AGND pad to the ground plane on the bottom PCB layer.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Determine power losses and thermal requirements of the board For example: VIN = 24𝑉, VOUT = 3.3𝑉, IOUT = 1.5𝐴, TAMB(MAX) = 85°C and TJ(MAX) = 125°C TAMB(MAX) is the maximum air temperature surrounding the module. TJ(MAX) is the maximum value of the junction temperature according to the “OPERATING CONDITIONS” limit. The goal of the calculation is to determine the characteristics of the required heat sink.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Power Loss: VIN = 24V @ TAMB = 25°C 6 VOUT = 15V, fSW = 1000 kHz VOUT = 12V, fSW = 800 kHz VOUT = 5.0V, fSW = 500 kHz VOUT = 3.3V, fSW = 400 kHz VOUT = 2.5V, fSW = 400 kHz Power Loss [W] 5 4 3 2 1 0 0 0.5 1.0 1.5 2.0 2.5 Output Current [A] 06D From the graph we read a power loss of 1.5W. Adding 20% results in a loss of 1.8W. Entering the values in formula (16) results in: θCA(MAX) < 125°C − 85°C − 6.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module PROTECTIVE FEATURES Over current protection (OCP) For protection against load faults, the MagI³C Power Module incorporates cycle-by-cycle current limiting. During an overcurrent condition the output current is limited and the output voltage is reduced, as shown in Figure 14. As the output voltage drops more than 8% below the set point, the PG signal is pulled low.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module APPLICATIONS Typical Application Circuit 26 VIN 35 RUVLO1 27 CIN2 CIN1 31 RUVLO2 VIN PG FB RT/CLK 36 COUT1 AGND COUT2 SSCHO SS/TRK 29 RRT RSET Module EN/UVLO PGND VOUT VOUT 28 CSS Recommended component values specified at TA = 25°C we-online.com VOUT 12V 5V 3.3V VIN 15V to 50V 8V to 50V 7V to 36V RSET 140kΩ 52.3kΩ 31.6kΩ RUVLO1 174kΩ 174kΩ 174kΩ RUVLO2 15.4kΩ 31.6kΩ 40.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module EVALUATION BOARD SCHEMATIC R1 LED1 R2 Optional input filter IC1 Lf 26 VIN 35 RUVLO1 27 CIN1 Cf CIN2 RSYNC CSYNC CIN3 EXT.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module HANDLING RECOMMENDATIONS 1. f SOLDER PROFILE 1. Only Pb-Free assembly is recommended according to JEDEC J-STD020. 2. Measure the peak reflow temperature of the MagI³C power module in the middle of the top view. 3. Ensure that the peak reflow temperature does not exceed 245°C ±5°C as per JEDEC J-STD020. 4. The reflow time period during peak temperature of 245°C ±5°C must not exceed 30 seconds. 5.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module PHYSICAL DIMENSIONS (mm) Package Type: BQFN-41 (9 x 11 x 2.8mm) we-online.com Würth Elektronik eiSos GmbH & Co. KG - Data Sheet - REV 1.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module recommended soldering pad solder past recommendation 150 µm we-online.com Würth Elektronik eiSos GmbH & Co. KG - Data Sheet - REV 1.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module PACKAGING Reel (mm) 20P we-online.com Würth Elektronik eiSos GmbH & Co. KG - Data Sheet - REV 1.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module Tape (mm) BQFN-41 ±0,1 ±0,1 ±0,05 ±0,1 ±0,05 9,35 11,35 0,30 3,10 1,55 ±0,10 Marking Marking Marking Marking Marking Marking 22P we-online.com Würth Elektronik eiSos GmbH & Co. KG - Data Sheet - REV 1.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module DOCUMENT HISTORY Revision Date 1.0 May 2016 Description Comment Release of final version CAUTIONS AND WARNINGS The following conditions apply to all goods within the product series of MagI³C of Würth Elektronik eiSos GmbH & Co. KG: General: All recommendations according to the general technical specifications of the data-sheet have to be complied with.
WPMDU1251501 / 171021501 MagI³C Power Module VDRM - Variable Step Down Regulator Module IMPORTANT NOTES The following conditions apply to all goods within the product range of Würth Elektronik eiSos GmbH & Co. KG: 1. General Customer Responsibility Some goods within the product range of Würth Elektronik eiSos GmbH & Co. KG contain statements regarding general suitability for certain application areas.