A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
Example
The output voltage of A1085-ADJ adjustable version satisfies this followed equation:
OUT=VREF x (1+R2/R1) + IADJ x R2
V
We can ignore IADJ because IADJ (about 50uA) is much less than the current of R1 (about 4mA).
The value of R1 should be in the range 120Ω ~ 200Ω to assure chip working normally without any load. To
assure the electrical performance showed in Table 1, the output than 4mA, the best working condition is to
assure that the output current exceeds 10mA.
(Schematic 1)
Adjustable Version
VOUT=VREF x (1+R2/R1) + IADJ x R2
Fixed Output Version
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
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