Feature

Input voltage range: 4.75 V to 5.25 v

VLDoin voltage range: 1.2 V to 3.6 v

3-a receiver/power terminal regulator

Including drooping compensation

Only 20-μF ceramic output

Capacitors

Soft closure in high Z and S5 in S3

1.2-V input (VLDoin) helps reduce

Power consumption

Comprehensive separation orbit

VTT and VTTREF

Remote sensing (VTTSNS)

The ± 20 MV accuracy of VTT and VTTREF

10 millilitious buffer reference voltage (VTTREF)

built -in soft start, UVLO and OCL

Hot shutdown

Support JEDEC specification

Application

DDR2 memory termination

SSTL-2, SSTL-18 and HSTL terminal

Explanation

TPS51100 is a 3-A receiver/source tracking terminal regulator. It is a low -cost/low external component counting system, and space is a premium.

TPS51100 keeps fast transient response only 20-micro F (2 × 10 micro F) ceramic output capacitors. The TPS51100 supports remote sensing functions and all functions required for DDR and DDR2 VTT bus terminals. In addition, the TPS51100 includes the integrated sleep status control to place the HIGH-Z (hung RAM) and softly close the VTT and VTTREF IN S5 (hanging to the disk). TPS51100 at the thermal efficiency 10-needle MSOP power board #63722; the specified temperature is -40 ° C to 85 ° C.

Simplified box diagram

Detailed description

VTT receiver/source transfer device

TPS51100 is a 3- 3- A receiver/source tracking terminal regulator is designed for low -cost, low external component systems. The space of this system is very superior, such as laptop applications. TPS51100 integrates high -performance low -loss linear stabilizers, which can generate and absorb currents with up to 3 A. The VTT linear regulator uses the ultimate fast response feedback circuit, so small ceramic capacitors are enough to maintain the tracking of VTTREF under all conditions including fast load transient state0 MV. In order to achieve the strict adjustment of the minimum tracking resistance effect, the remote sensing terminal VTTSNS should be connected to the positive node of the VTT output capacitor as a separate tracking of VTT high -current lines.

VTTREF regulator

VTTREF block is composed of 1/2 points of frequency and LPF buffer on the film. This regulator can generate a current of up to 10 mA. Use 0.1 microns ceramic capacitors to bypass VTTREF to GND to ensure stable operation.

Soft starting

The soft startup function of VTT is achieved through current clamps. It allows the output capacitor to fill the low and constant current, so that the output voltage linearity is increased. Use the internal PowerGood signal to change the current limit threshold in two stages. When VTT exceeds the PowerGood threshold, the current limit is 2.2 A. When VTT is higher than (VTTREF-5%) or lower than (VTTREF+5%), the current limit is switched to 3.8 A. The threshold is usually VTTREF ± 5%(from external adjustment to internal) and ± 10%(when it falls outside). The soft startup function is completely symmetrical. It not only works between GND and VTTREF voltage, but also works between VDDQ and VTTREF voltage. Note that during the S3 state (S3 low, S5 high), the VTT output is in a high impedance state, and its voltage can be as high as VDDQ voltage, depending on external conditions. Note that VTT cannot start at full load conditions.

S3, S5 control and soft shutdown

S3 and S5 terminals should be connected to SLP_S3 and SLP_S5 signals, respectively. VTTREF and VTT are opened in S0 (S3 high, S5 high). When VTT is closed and high impedance (S3 low, S5 high) in the S3 state, VTTREF remains activated. In the S4/S5 state, both VTT and VTTREF output are closed and discharged to the ground through the internal MOSFET (both S3 and S5 are low levels).

Precautions for layout

Before the design of the TPS51100 design, please consider the following points.

VLDoin's input bypass container should be placed in a position near the pipe foot as close as possible, and there is a short and wide connection.

The output capacitor of the VTT should be placed near a short and wide -connected pin to avoid additional ESR and/or ESL tracking.

VTTSNS should be connected to the positive node of the VTT output capacitor as a separate channel with a large current power line. It is strongly recommended to avoid additional ESR and/or ESL. If the voltage of the load point is required, it is recommended to connect the output capacitor at this point. In addition, it is recommended to put any additional ESR and/or grounded trajectory ES between the GND pin and the output capacitorL drops to the minimum.

If the ESR of the VTT output capacitor is greater than 2 MΩ, consider adding LPF at VTTSN.

VDDQSNS can be connected separately from VLDoin. Remember, this induction potential is the reference voltage of VTTREF. Avoid any noise to generate a line.

The negative nodes of VTT output capacitors and VTTREF capacitors should be connected by avoiding public impedance with VTT source/exchange current.

GND (Signal GND) PIN node indicates the reference potential of VTREF and VTT output. Connect the ground to the negative nodes of VTT capacitors, VTTREF capacitors and VDDQ capacitors, and avoid additional ESR and/or ESL. GND and PGND (Power GND) should be isolated, and there is a single point connection between them.

In order to effectively remove the heat in the packaging, the thermal welding rings are prepared and welded to the packaged thermal pad. The widespread trace of component side copper connected to this hot soil will help spread the heat. Many of the pores with a diameter of 0.33 mm connected from the heat sink to the internal/solder side ground plane are applied to help heat dissipation.

Packaging information

Marketing status value is as follows:

Activity: Recommended for new for new Design product equipment.

Lifeboat: Texas instruments have been announced that the equipment will be stopped and the lifelong purchase period has taken effect.

Number: It is not recommended for new design. The equipment is supporting existing customers in production, but TI does not recommend using this part in new design.

Preview: The equipment has been released, but it has not been put into production. There may be or not. Over time: TI has stopped producing the device.

(2)

Ecological Plan-Planning Ecological Friendship Category: Leadless (ROHS), Leadless (ROHS Exemption) or green (ROHS AMP; No SB/BR)

To be determined: Unfielded lead/green conversion plan.

Leadless (ROHS): The term lead " or "lead " of titanium refers to semiconductor products compatible with the current ROHS requirements of all 6 substances