SN65LVPE502CP

SLLSE79B

– MARCH 2011 – REVISED FEBRUARY 2012

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DETAILED DESCRIPTION

Programmable EQ, De-Emphasis and Amplitude Swing

The SN65LVPE502CP is designed to minimize signal degradation effects such as crosstalk and inter-symbol

interference (ISI) that limits the interconnect distance between two devices. The input stage of each channel

offers selectable equalization settings that can be programmed to match loss in the channel. The differential

outputs provide selectable de-emphasis to compensate for the anticipated distortion USB 3.0 signal will

experience. Level of de-emphasis will depend on the length of interconnect and its characteristics. The

SN65LVPE502CP provides a unique way to tailor output de-emphasis on a per channel basis with use of DE and

OS pins. All Rx and Tx equalization settings supported by the device are programmed by six 3-state pins as

shown in Table 2.

Low Power Modes

Device supports three low power modes as described below

1. Sleep Mode

Initiated anytime EN_RXD undergoes a high to low transition and stays low or when device powers up with

EN_RXD set low. In sleep mode both input and output terminations are held at HiZ and device ceases

operation to conserve power. Sleep mode max power consumption is 1mW, entry time is 2

µs, device exits

sleep mode to Rx.Detect mode after EN_RXD is driven to Vcc, exit time is 100

µs max.

2. RX Detect Mode--When no remote device is connected

Anytime LVPE502CP detects a break in link (i.e. when upstream device is disconnected) or after power-up

fails to find a remote device, LVPE502CP goes to Rx Detect mode and conserves power by shutting down

majority of its internal circuitry. In this mode input termination for both channels are driven to Hi-Z. In Rx

Detect mode device power is

<10mW (TYP) or less than 5% of its normal operating power . This feature is

very useful in saving system power in mobile applications like notebook PC where battery life is critical.

Anytime an upstream device gets reconnected the redriver automatically senses the connection and goes to

normal operating mode. This operation requires no setting to the device.

3. U2/U3 Mode

With the help of internal timers the device tracks when link enters USB 3.0 low power modes U2 and U3; in

these modes link is in electrical idle state. LVPE502CP will selectively turn-off internal circuitry to save on

power. Typical power saving is about 75% lower than normal operating mode. The device will automatically

revert to active mode when signal activity (LFPS) is detected.

Receiver Detection

At Power Up or Reset

After power-up or anytime EN_RXD is toggled, RX.Detect cycle is performed by first setting Rx termination for

each channel to Hi-Z, device then starts sensing for receiver termination that may be attached at the other end of

each TX.

If receiver is detected on both channel

•

If no receiver is detected on one or both channels

•

The transmitter is pulled to Hi-Z

•

The channel is put in low power mode

•

Device attempts to detect Rx termination in 12 ms (TYP) interval until termination is found or device is put in

sleep mode

During U2/U3 Link State

Rx detection is also performed periodically when link is in U2/U3 states. However in these states during Rx

detection, input termination is not automatically disabled before performing Rx.Detect. If termination is found

device goes back to its low power state if termination is not found then device disables its input termination and

then jumps to power-up RX.Detect state.

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