AAT1143(2005) 查看數據表（PDF） - Advanced Analogic Technologies

零件编号

产品描述 (功能)

生产厂家

AAT1143
(Rev.:2005)

1MHz 400mA Step-Down Converter

Advanced Analogic Technologies 

AAT1143

1MHz 400mA Step-Down Converter

Input Capacitor

Input Ripple VPP = 25mV

1

1

CIN = ⎛ VPP

⎝ IO

- ESR⎞⎠ · 4 · FS

=

⎛ 25mV

⎝ 0.4A

- 5mΩ⎞⎠ · 4 · 1MHz

= 4.75µF

IRMS =

IO

2

= 0.2Arms

P = esr · IRMS2 = 5mΩ · (0.2A)2 = 0.2mW

AAT1143 Losses

PTOTAL

=

IO2

·

(RDSON(HS)

·

VO

+ RDSON(LS)

VIN

·

[VIN

-VO])

+ (tsw · F · IO + IQ) · VIN

0.42 · (0.725Ω · 1.8V + 0.7Ω · [4.2V - 1.8V])

=

4.2V

+ (5ns · 1.0MHz · 0.4A + 50µA) · 4.2V = 122mW

TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + (160°C/W) · 122mW = 104.5°C

16

1143.2005.09.1.7

Share Link: