L6730 datasheet(16/52 Pages) STMICROELECTRONICS

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Device description

L6730 - L6730B

16/52

Doc ID 11938 Rev 3

5.4

Internal and external references

It is possible to set two internal references, 0.6 V and 1.2 V, or provide an external reference

from 0 V to 2.5 V. The maximum value of the external reference depends on the VCC: with

VCC = 4 V the clamp operates at about 2 V (typ.), while with VCC greater than 5 V the

maximum external reference is 2.5 V (typ).

●

VEAREF from 0% to 80% of VCCDR −> External reference

●

VEAREF from 80% to 95% of VCCDR −> VREF = 1.2 V

●

VEAREF from 95% to 100% of VCCDR −> VREF = 0.6 V

Providing an external reference from 0V to 450 mV the output voltage will be regulated but

some restrictions must be considered:

●

The minimum OVP threshold is set at 300 mV.

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The under-voltage-protection doesn’t work.

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The PGOOD signal remains low.

To set the resistor divider it must be considered that a 100 k

Ω pull-down resistor is

integrated into the device (see Figure 7.). Finally it must be taken into account that the

voltage at the EAREF pin is captured by the device at the start-up when Vcc is about 4 V.

Figure 6.

Bypassing the LDO

L6730 Datenblatt(PDF) 16 Page - STMicroelectronics