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Table 1-1 highlights the latest POL DC/DC converters with integrated MOSFETs and controllers suitable for Tiger Lake applications. The suggested devices are selected to accommodate different input voltage and control mode requirements over a wide range of output current. The featured devices in the left column accommodate a maximum input voltage of 22 V or greater, and are designed to achieve fast load-transient response with an adaptive on-time control mode, high light and full-load efficiency, and low quiescent current. Several devices include an integrated programmable voltage identification (VID) supporting the processor's adaptive voltage requirements. The alternate devices in the right column employ fixed-frequency current-mode control with frequency synchronization useful in noise-sensitive industrial applications, and operate up to a 17 V input. If VID is required with alternative devices, consider the LM10011 VID voltage programmer in addition to the converter's resistor divider network.
Featured P/N (1) | Rail | Current | Type | Note | Alternate P/N(2) | Alternate P/N Power Module |
---|---|---|---|---|---|---|
TPS51285A | V5A | ≤20A & 100mA LDO each Rail | Dual Controller & 2 LDOs | System Power | TPS51220A | |
V3P3 | ||||||
TPS51395 | V5A | ≤8A & 100mA LDO | Converter & LDO | System Power | TPS543820 | |
TPS51393 | V3P3 | |||||
TPS51215A | VCCIN_AUX | ≤32A | Controller | I/O power, 2-bit VID (0V support) | - | - |
TPS51372 | V1P8A, Optional bypass | ≤6.5A | Converter | 2-bit VID | TPS543620 | |
General Purpose DC/DC Converters | ||||||
TPS51219 | Various | ≤25A | Controller | General | TPS543B20 | |
TPS51397A | Various | ≤10A | Converter | General | TPS542A52 | |
TPS51396A | Various | ≤8A | Converter | General | TPS543820 | TPSM84824 |
TPS566335 | Various | ≤6A | Converter | General | TPS543620 | TPSM84424 |
TPS56339 | Various | ≤3A | Converter | General | TPS543320 | |
DDR Memory Power Solutions | ||||||
TPS51486 | VDDQ | ≤8A | Multi-Channel Converter | DDR4 Memory | TPS65295 | |
VPP | ≤1A | |||||
VTT | ±1A | |||||
VTT_REF | 10mA | - | ||||
TPS51487X | VDD1 | ≤8A | Multi-Channel Converter | LPDDR4/X Memory | TPS65296 | TPSM84824 |
VDD2 | ≤1A | TPS82150 | ||||
VDDQ_TX | ≤1.5A | |||||
TPS51716 | VDDQ | ≤25A | Controller & LDO | DDR4 Memory | Consider General Devices with TPS51206 | |
VTT | ±2A | Use TPS51206 | ||||
VTT_REF | 10mA | Use TPS51206 | ||||
TPS51206 | VTT | ±2A | LDO | DDR4 Memory | Use TPS51206 | Use TPS51206 |
VTT_REF | 10mA |
The POL regulators generating low voltages from an array of batteries must employ an energy-saving pulse-skipping technique now referred to as Eco-Mode. The inductor current in a synchronous-buck converter is a triangle wave. As the output current decreases from a heavy-load condition, the inductor current is reduced and the rippled valley of the triangle wave eventually touches the zero level at the boundary between continuous conduction-mode (CCM) and discontinuous conduction node (DCM). With Eco-Mode, the rectifying MOSFET is turned off when the converter detects zero current in the inductor. As the load current further decreases, the on-time is held nearly constant so that the off-time is extended, and the switching frequency is reduced to maintain regulation. As a result, the power MOSFETs and inductor are idle for longer time periods and conduction losses are greatly reduced. DC/DC converters and controllers with low quiescent current will have improved light-load efficiency performance and extended battery run-time, since less power is dissipated within the IC. The TPS51825A features Ultra Low Quiescent current (ULQ) of 25-uA for longer battery life in system stand-by mode. Figure 2-1 shows 90% efficiency with 7.4-V input and 5-V output at 1-mA, illustrating the combined affects of Eco-Mode and ULQ.
The TPS51215A supports a 2-bit VID and Low Power Mode(LPM) to dynamically change the output voltage to satisfy Intel IMVP8/9 applications for VCCIN_AUX, VCCIO_0, and VCCIO_1_2 rails. A fixed 0-V output voltage and up to three voltage levels can be programmed externally with a voltage divider circuit. The device can also be configured to provide a 1-bit VID output voltage. Please see the TPS51215A data sheet for more information.
Since the load profile can change dramatically in industrial PC applications, it is important to consider AC transient performance. Choosing a DC/DC converter with a fast transient response using non-linear control techniques, such as constant on-time or D-CAP3, allows a fast transient response with minimal output capacitance. A converter using D-CAP3 control mode has three primary considerations for deciding the value of the output capacitance: transient (which includes load step and slew rate of the load step), output ripple, and stability. In applications where the load transient is stringent, the output capacitance is predominantly driven by the transient requirement. For a D-CAP3 based design, there is a minimum capacitance requirement in terms of small signal stability. This requirement prevents subharmonic, multiple-pulsing behavior in the modulator. Figure 4-1 shows the transient performance of the 8-A TPS51395 with a 5-V output, less than 100mV overshoot, and less than a 30µs recovery with output capacitance of 0.1 µF and 4x22 µF. The 0.8-A to 7.2-A load step has a slew rate of 2.5-A/µs.
The TPS51215A supplying VCCIN_AUX features adaptive on-time D-CAP2 control allowing ceramic output capacitors and acheives a fast load transient response shown in Figure 4-2 under the noted conditions below the waveform. The over-voltage and under-voltage test results also meet the target design specification, and the results are shown in Table 4-1 under the same conditions as the TPS51215A load transient waveform. The TPS51215A waveform conditions are VIN=12.6V, slew rate=12A/µs, FSW =600kΩ, L=0.22µH, and COUT=220µF + 22*12µF .
Voltage Rail | Type | Load Transient | Validation Result (V) | Target (V) |
---|---|---|---|---|
1.8V | Undershoot | 0A to 16A | 1.67 | 1.62 |
Overshoot | 16A to 0A | 1.858 | 1.89 | |
1.8V | Undershoot | 17A to 29A | 1.678 | 1.62 |
Overshoot | 29A to 17A | 1.882 | 1.89 |
Integrated circuit packaging technology must keep pace with semiconductor wafer fabrication as process technology advances. TI has released flip-chip on leadframe packaging that reduce package footprint, power loss, and parasitic effects. Traditional bond wires are replaced with copper posts attached directly to the leadframe which shortens current path from the IC to the lead frame, which allows a larger die in the small package cavity, reduced package resistance, and reduced parasitic package inductance loops. Consider the 6-A TPS566335, housed in a small 2x3mm QFN package. Figure 5-1 shows ample pins for power conversion and I/O features while maintaining a 0.5mm pin pitch, allowing simplified circuit board manufacturing.