IRDC3137 1 rev. 1.0 06/30/03 www.irf.com specification data introduction iru3137 evaluation board user guide input/output connections the iru3137 controller ic is designed to provide a low cost and high performance synchronous buck regulator for on-board dc to dc converter applications. the out- put voltage can be set as low as 0.8v and higher voltage can be obtained with an external voltage divider. high peak current gate drivers provide fast switching transi- tion for applications requiring high output current in the range of 15a to 20a. this device features an internal 200khz oscillator, un- der-voltage lockout for both vcc and vc supplies, an external programmable soft-start function as well as out- put under-voltage detection that latches off the device when an output short is detected. v in = 5v v out = 2.5v i out = 15a d v out = 75mv f s = 200khz the following is the input/output connections: inputs: jp1: input (+5v), gnd jp4: input (+12v), gnd outputs: jp2: v out (+2.5v) jp3: gnd the connection points is shown in figure 1. connect the power supply cables according to this figure, minimize wire lengths to reduce losses in the wire. test point j1 provides easy connections for the oscilloscope voltage probe to monitor the output voltage. supply voltage: v cc = v c = 12v note: for proper operation, +5v supply should ramp up first.
2 rev. 1.0 06/30/03 IRDC3137 www.irf.com figure 1 - connection diagram of evaluation-board for iru3137. connection diagram power supply gnd +12v 1a supply load 0 - 15a power supply gnd +5v 10a supply
IRDC3137 3 rev. 1.0 06/30/03 www.irf.com the four layers for iru3137 evaluation board are shown in figures 2.1-2.4. the layout is designed both for direct fet package and soic package for power mosfets. the input capacitors are all located close to the mosfets. all the decoupling capacitors and feedback components are located close to ic. the feedback re- sistors are tied to the output voltage at the point of regu- lation. the middle layers are dedicated to power ground and analog ground. analog ground is kept separated from the power ground and it is connected at a single point as shown in figure 2.3. layout figure 2.1 - top layer of evaluation-board for iru3137.
4 rev. 1.0 06/30/03 IRDC3137 www.irf.com figure 2.2 - middle layer 1. figure 2.3 - middle layer 2. figure 2.4 - bottom layer. layout
IRDC3137 5 rev. 1.0 06/30/03 www.irf.com schematic figure 3 - schematic of evaluation-board for iru3137. hdrv gnd vc comp vcc ss ldrv fb u1 iru3137 jp1 6 7 8 d2 q2 q1 c9 r6 4.7 v c10 c11 c21 l2 2.17uh jp2 vout vout c12 1uf r11 1k +12v gnd jp3 gnd c22 c25 gnd c1 150uf c13 c19 c23 c20 l1 1uh d3 bat54 r9 5 3 2 1 4 jp4 +5v gnd c6 r1 open r2 0 v 1uf 150uf d1 bat54sct r14 open c4 1uf c5 open c8 0.1uf c3 1uf r7 r10 r8 30k 2.15k c13 c15 c16 c14 c17 3300pf 47p 330uf 330uf 330uf 470pf open open open open open open open 150uf 150uf n/a j1 n/a n/a
6 rev. 1.0 06/30/03 IRDC3137 www.irf.com bill of material ref desig description value qty part# manuf 2 1 2 1 1 1 5 3 1 1 1 1 4 1 1 1 1 1 4 6 4 1 q1, q2 u1 d1, d2 d3 l1 l2 c1,18,19,20,23 c10,11,21 c8 c15 c9 c13 c3,4,6,12 r6 r8 r9 r11 r2 r1,7,10,14 c5,14,16,17,22,25 jp1,jp2,jp3,jp4 j1 mosfet controller schottky diode schottky diode inductor inductor capacitor, poscap capacitor, poscap capacitor capacitor, ceramic capacitor, ceramic capacitor, ceramic capacitor, ceramic resistor resistor resistor resistor resistor resistor capacitor irf7832 iru3137cs n/a open bat54 d03316p-102hc etqp6f2r5bfa 6tpc150m 6tpc330m ecj-2vf1e104z ecj-2vb1h332k ecj-2vc1h471j ecj-2vc1h470j ecj-2vf1c105z ed1973-nd 131-5031-00 ir ir ir ir coilcraft panasonic sanyo sanyo panasonic panasonic panasonic panasonic panasonic digikey tektronix 30v, 4m v , 15a synchronous pwm fast switching 1 m h, 10a 2.17 m h, 17a 150 m f, 6.3v 330 m f, 6.3v 0.1 m f, y5v, 25v 3300pf, x7r, 50v 470pf, x7r, 50v 47pf, npo 1 m f, y5v, 16v 4.7 v , 1% 2.15k, 1% 30k, 1% 1k, 1% 0 v n/a open n/a open 2-pos terminal
IRDC3137 7 rev. 1.0 06/30/03 www.irf.com figure 7 - normal condition at 15a. ch1: output voltage ripple (20mv/div) ch2: hdrv ch3: ldrv ch4: inductor current (5a/div) figure 5 - normal condition at n/l. ch1: output voltage ripple (20mv/div) ch2: hdrv ch3: ldrv ch4: inductor current (2a/div) figure 6 - transient load response at i out =0a - 15a. ch1: v out ch4: i out (5a/div) figure 4 - transient load response at i out =0a - 8a. ch1: v out ch4: i out (5a/div) typical operating characteristics
8 rev. 1.0 06/30/03 IRDC3137 www.irf.com ir world headquarters: 233 kansas st., el segundo, california 90245, usa tel: (310) 252-7105 tac fax: (310) 252-7903 visit us at www.irf.com for sales contact information data and specifications subject to change without notice. 02/01 figure 9 - start-up. ch2: v ss (soft-start voltage) ch3: v out ch4: i out (5a/div) figure 8 - shutdown by pulling down the soft-start pin. ch1: v out ch2: hdrv ch3: ldrv ch4: i out (10a/div) typical operating characteristics figure 10 - application circuit efficiency at ambient temperature. 5v to 2.5v 0 20 40 60 80 100 120 0 2 4 6 8 10 12 14 16 18 output current (a) efficiency (%)
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