XCM524 Datasheet, PDF (18/52 Pages) Torex Semiconductor – 600mA Synchronous Step-Down DC/DC Converter + 500mA LDO with Delay Function Voltage Detector

XCM524 Series
˙NOTE ON USE (Continued)
16.ç Please note the L value of the coil. The IC may enter unstable operation if the combination of ambient temperature, setting
voltage, oscillation frequency, and L value are not adequate. ç
<External Components>
˔The Range of L Valueç
f_OSC
V_DCOUT
L Value
3.0MHz
0.8VʽV_DCOUTʽ4.0V 1.0ЖHʙ2.2ЖHç
1.2MHz
V_DCOUTʽ2.5V
2.5VʻV_DCOUT
3.3ЖHʙ6.8ЖHç
4.7ЖHʙ6.8ЖHç
*When a coil less value of 4.7μH is used at when a coil
less value of 1.5μH is used at f_OSC=3.0MHz, peak coil
current more easily reach the current limit ILMI. In this
case, it may happen that the IC can not provide 600mA
ç ^{output current.ç}
17. Under input-output voltage differential is large, operating may become unstable at transition to continuous mode.
Please verify with actual parts.
<External Components>
˔Instructions of pattern layoutsç
1.ç Please use this IC within the stated absolute maximum ratings. The IC is liable to malfunction should the ratings be
exceeded.
2.ç In order to stabilize V_IN1ɾV_IN2ɾDCOUTŋV_ROUT voltage level, we recommend that a by-pass capacitor (C_IN1ɾC_IN2ɾC_L1ɾ
C_L2) be connected as close as possible to the V_IN1ɾV_IN2ɾDCOUTŋV_ROUT and GNDŋV_SS pins.
3. Please mount each external component as close to the IC as possible.
4.ç Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit
impedance.
5. V_SSʢAGNDɾPGNDɾV_SSʣground wiring is recommended to get large area. The IC may goes into unstable operation as
a result of V_SS voltage level fluctuation during the switching.
6.ç This series’ internal driver transistors bring on heat because of the output current (I_OUT) and ON resistance of driver
transistors.
˔Recommended Pattern Layout
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