NR131A Datasheet, PDF (9/15 Pages) Sanken electric – Ultra light load high efficiency

Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR130A series
Tentative
Sep/10/2013
Example Application Circuit
For NR131A
NR131A
C1, C2: 10μF / 25V, C4, C5: 22μF / 16V, C7: 0.1μF, C9:1800pF, C11: 220pF(Option), R1: 510kΩ , R3: 10Ω, R4: 36 kΩ, R5: 27kΩ
(VO=5.0V), R6: 12kΩ, R7:510kΩ(Option), D1: SJPJ-L4, L1: 10μH
For NR132A
NR132A
C1, C2: 10μF / 25V, C4, C5: 22μF / 16V, C7: 0.1μF, C9:1800pF, C11: 220pF(Option), R1: 510kΩ , R3: 10Ω, R4: 36 kΩ, R5: 27kΩ
(VO=5.0V), R6: 12kΩ, R7:510kΩ(Option), D1: SJPJ-L4, L1: 10μH
A design guide for add-on parts around of the NR130A series.
(1)Diode D1
・The schottky-barrier diode must be used for D1. If other diodes like fast recovery diodes are used, IC may be
damaged because of the reverse voltage applied by the recovery voltage or ON voltage.
(2)Choke coil L1
・If the winding resistance of the choke coil is too high, the efficiency may go down to the extent that it is out of the rating.
・As the start current of the over current protection is approximately 4A, attention must be paid to the heating of the choke
coil by the magnetic saturation due to overload or short-circulated load.
(3)Capacitor C1( C2), C4(C5), C9
・As large ripple current across C1 (C2) and C4 (C5), capacitors with high frequency and low impedance for SMPS must be
used. Especially when the impedance of C4 (C5) is high, the switching waveform may not be normal at low temperature.
・C9 is a capacitor for soft start. In case soft start function is not used, please keep Pin No.2 open.
Rev.1.1
SANKEN ELECTRIC CO., LTD.
9
http://www.sanken-ele.co.jp