UVLO/stbdy pin functionning modes

Due to the wide supply voltage range of the TD310, the UVLO function (Under Voltage Lock Out) is

externally adjustable by a resistor bridge.

The bridge rate can be calculated in relation with the expected UVLO protection level as follows :

R1

R1

1.2V (where R1 is the lower resistor of the bridge)

The internal resistor sets the default UVLO value to 12V (*) and might influence the external bridge rate if

the values of the external resistors are too high.

The standby threshold value depends of the UVLO value as follows :

resistor (ex 150k

Ω).

The following table summarizes the functions of the TD310 :

Pin

16

9/11

5

2/3/4

15/14

/13

6

7/8/10

Configuration

UVLO/stdby

Sense+/Sense- Enabl

e

In A/B/C

Out

A/B/C

Alarm

Op.

Amp.

Consumption

Normal

1

H

+ > -

XXL

L

OK

H (1.5mA)

+< -

HIN

IN

H

LX

L

Stdby

2

L

+> -

XXL

L

HZ

L (30

µA)

+< -

H

UVLO

3

M

X

X

X

L

L

OK

H

Configuration 1 : UVLO/stdby = H

The TD310 is in a normal consumption state (1.5mA), the operational amplifier is normally functionning

and the buffer outputs are determined by the sense comparator inputs, the enable inputs and the buffer

inputs.

Configuration 2 : UVLO/stdby = L

The TD310 is in a low consumption state (standby mode 30

µA), the buffer outputs are set to low state and

the operational amplifier is in high impedance state.

Configuration 3 : UVLO/stdby = M

state and the operational amplifier is normally functionning but the buffer outputs and the alarm pin are set

to low state.

(*)

If the UVLO level remains unadjusted, it is recommended to bypass the UVLO/stdby pin with a 1nF capacitor.

(**)

TD310

4/9