SP207H datasheet(7/14 Pages) SIPEX

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TGoddard/SP207H/9614R0

SP207H/SP211H High–Speed Transceivers

Power

Receiver

Up/Down

Outputs

Enable

Tri–state

Down

Tri-state

Down

Tri–state

SHUTDOWN MODE

The SP207HB, SP211H and SP211HB all fea-

ture a control input which will disable the device

and reduce the power supply current to less than

µA, making the parts ideal for battery–pow-

ered systems. In the “shutdown” mode the re-

ceivers and transmitters will both be tri–stated.

The V+ output of the charge pump will discharge

to V

CC , and the V

– output will discharge to

ground.

For complete shutdown to occur and the 10

µA

power drain to be realized, the following condi-

tions must be met:

• +5V must be applied to the SD pin

• ENABLE must be either 0V, +5.0V or not

connected

• the transmitter inputs must be either +5.0V

or not connected

• V

CC must be +5V

• Receiver inputs must be >0V and <+5V

ENABLE

The SP207HB, SP211H and SP211HB feature

an enable input pin, which allows the receiver

VCC = +5V

+10V

VSS Storage Capacitor

VDD Storage Capacitor

–

Table 2. Truth Table for SP2xxH

Power

Receiver

Up/Down

Outputs

Enable

Tri–state

Down

Enable

Down

Tri–state

Table 3. Wake–Up Truth Table for SP2xxHB

Figure 5. Charge Pump — Phase 4

outputs to be either tri–stated or enabled. This

can be especially useful when the receiver is tied

directly to a microprocessor data bus. The en-

able is active low; that is, 0V applied to the

ENABLE pin will enable the receiver outputs.

WAKEUP FUNCTION

The SP207HB and SP211HB have a wake–up

feature that keeps all the receivers in an enabled

state when the device is in the shutdown mode.

With only the receivers active during shutdown,

the devices draw 5–10

µA of supply current. A

typical application of this function would be

where a modem is interfaced to a computer in a

power–down mode. The ring indicator signal

from the modem could be passed through an

active receiver that is in the shutdown mode.

The ring indicator signal would propagate

through the receiver to the power management

circuitry of the computer to power up the micro-

processor and the SP207HB/SP211HB drivers.

After the supply voltage to the transceivers

reaches +5.0V, the SHUTDOWN pin can be

disabled. All receivers that are active during

shutdown maintain 500mV (typ.) of hysteresis.

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