Technical Note

4/16

BU9829GUL-W

www.rohm.com

2010.09 - Rev.A

© 2010 ROHM Co., Ltd. All rights reserved.

●

LDO regulator AC operating characteristics

Parameter

Symbol

Specification

Unit

Test condition

Min.

Typ.

Max.

Vcc1 Rise Time

-

-

5

msec

VCC1 x 0%→VCC1 x 95% point

LDOEN Wait Time

15

-

-

msec

VCC1 x 0%point→ LDOEN=High

●

Output voltage depend on VSET bit

The 2bit data are stored into the VSET memory and output voltage change among VOUT1～VOUT4.

VSET data are Written into non-volatile memory array. Initial VSET data is 1,0 in VSET[1:0] and VOUT is 2.9V.

STEP

VOUT(typ.) [V]

VSET1

VSET0

VOUT1

VOUT2

VOUT3

VOUT4

3.0

2.9

2.8

2.7

1

1

0

0

1

0

1

0

●

Input power supply regulation timing

①

Using EEPROM PART

In case of using EEPROM part, be sure to raise Vcc1 up to operating voltage. In this time, Vcc2 has no connection with

operating.

②

Using LDO regulator part

In case of using LDO regulator part, be sure to raise Vcc1 and Vcc2 up to operating voltage.

After rising Vcc1, wait 15msec and rising LDOEN.

When LDOEN is raised, Vcc1 must be operating voltage.

LDO regulator

Power Supply

Not

Operating

Vcc1

EEPROM

Power Supply

Vcc2

LDOEN

tVcc1:MAX 5msec

tVcc1:MAX 5msec

Not

Operating

Not

Operating

Operating

Operating

Fig.4 Using EEPROM Part, Regulation Timing

Fig.5 Using LDO Regulator Part, Regulation Timing

Vcc2

LDOレギュレータ部電源

Vcc1

EEPROM部電源

動作不可

EEPROM動作可能範囲

動作不可

EEPROM動作可能範囲

動作不可

EEPROM

Power Supply

Not

Operating

Operating

Not

Operating

Operating

Not

Operating

LDO regulator

Power Supply