MC34708 datasheet(69/159 Pages) FREESCALE

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Analog Integrated Circuit Device Data



Freescale Semiconductor

MC34708

Functional Block Description

7.5.6.6

VREFDDR

VREFDDR is an internal PMOS half supply Voltage Follower. The output voltage is at one half the input voltage. It’s typical

application is as the VREF for DDR memories. A filtered resistor divider is utilized to create a low frequency pole. This divider then

utilizes a voltage follower to drive the load.

tON-VPLL

Turn-on Time

• Enable to 90% of end value VIN = VINMIN, VINMAX IL = 0

120

µs

tOFF-VPLL

Turn-off Time

• Disable to 10% of initial value VIN = VINMIN, VINMAX, IL = 0

0.05

VPLLOS-

START

Start-up Overshoot

•VIN = VINMIN, VINMAX IL = 0

1.0

2.0

VPLL-LO

TRANSIENT

Transient Load Response

•VIN = VINMIN, VINMAX

VPLL-LI

TRANSIENT

Transient Line Response

•IL = 75% of ILMAX

5.0

8.0

Table 58. VREFDDR Electrical Specification

Characteristics noted under conditions BP = 3.6 V, VBUS = 5.0 V, -40 C  TA  85 C, unless otherwise noted. Typical values

at BP = 3.6 V and TA = 25 °C under nominal conditions, unless otherwise noted.

Symbol

Characteristic

Min

Typ

Max

Unit

Notes

GENERAL

VREFFDDRIN Operating Input Voltage Range VINMIN to VINMAX

1.2

1.8

IREFDDR

Operating Current Load Range ILMIN to ILMAX

0.0

VREFDDR ACTIVE MODE – DC

VREFDDR

Output Voltage VOUT

•VINMIN < VIN < VINMAX ILMIN < IL < ILMAX

0.6

VIN/2

0.9

VREFDDRTOL Output Voltage tolerance

•VINMIN < VIN < VINMAX IL = 1.0 mA

-6.5

6.5

(58)

VREFDDR

LOPP

Load Regulation

•1.0 mA < IL < ILMAX For any VINMIN < VIN < VINMAX

5.0

mV/mA

IREFDDRQ Quiescent Current

•VINMIN < VIN < VINMAX IL = 0

8.0

µA

VREFDDR ACTIVE MODE – AC

tON-VREFDDR Turn-on Time

• Enable to 90% of end value VIN = VINMIN, VINMAX IL = 0

100

µs

tOFF-

VREFDDR

Turn-off Time

• Disable to 10% of initial value VIN = VINMIN, VINMAX, IL = 0

0.05

VREFDDROS Start-up Overshoot

•VIN = VINMIN, VINMAX IL = 0

1.0

2.0

Table 57. VPLL Electrical Specification

Characteristics noted under conditions BP = 3.6 V, VBUS = 5.0 V,-40 C  TA  85 C, unless otherwise noted. Typical values at

BP = 3.6 V and TA = 25 °C under nominal conditions, unless otherwise noted.

Symbol

Characteristic

Min

Typ

Max

Unit

Notes

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