SLVAEG1A August 2019 – May 2021 TLV62568 , TLV62568A , TPS62840
PARAMETER | ARCHITECTURE A | ARCHITECTURE B | ARCHITECTURE C |
---|---|---|---|
IQ (Load = 0 A, Device Enabled) | 34 µA | 2.7 mA | 75 nA |
Light Load (ILOAD = 10 µA) | |||
System Efficiency | 10% | 0.1% | 93% |
Stage 1 Ripple | 22.4 mV | 6.0 mV | 5.20 mV |
1.87% Accuracy | 0.50% Accuracy | 0.43% Accuracy | |
Architecture A at 10 µA load. Both pre- and post-LDO ripples shown in dark blue and light blue, respectively. LDO rejects > 50 dB at 20 Hz PFM frequency | Architecture B at 10 µA load. Ripple (dark blue) and FFT plot of ripple (red) showing expected PWM ripple at 1.5 MHz | Architecture C at 10 µA load. Both pre-and post-PI filter ripples shown in dark blue and light blue, respectively. PI filter rejects only 3 dB at 100 Hz PFM frequency | |
Stage 2 Ripple | Noise Floor | N/A | 3.60mV |
<0.01% Accuracy | 0.30% Accuracy | ||
Full Load (ILOAD = 200 mA) | |||
System Efficiency | 61% | 91% | 88% |
Stage 1 Ripple | 28.0 mV | 6.0 mV | 3.68 mV |
2.33% Accuracy | 0.50% Accuracy | 0.31% Accuracy | |
FFT plot for ripple before LDO with 6.5 MHz bandwidth; cursors at low frequency 200 kHz peak and nominal switching frequency 1.5 MHz peak | FFT plot shown for FPWM ripple with 6.25 MHz bandwidth; cursors at nominal switching frequency 1.5 MHz and first harmonic 3 MHz peaks | FFT plot for ripple before PI filter with 6.25 MHz bandwidth; cursors at nominal switching frequency 1.8 MHz and first harmonic 3.6 MHz peaks | |
Stage 2 Ripple | 7.6 mV | N/A | Noise Floor |
0.63% Accuracy | <0.01% Accuracy | ||
FFT plot for ripple after LDO with 6.5 MHz bandwidth; cursors in same spots showing expected 22 dB rejection by TPS7A05 at 1.5 MHz | FFT plot for ripple after PI filter with 6.25 MHz bandwidth; cursors in same spots showing ripple after PI filter reaches noise floor of oscilloscope (85–90 dB) | ||
Thermal Images Taken after 20 minutes on with 200 mA load current | Infrared image showing TLV62568 heating to 28.8°C and TPS7A05 heating to 50.6°C after 20 minutes |
Infrared image showing TLV62568A heating to 22.5°C after 20 minutes | Infrared image showing TPS62841 heating to 23.3°C after 20 minutes |
Transient - Switching Load (Square wave, 50uA-200mA, 1kHz) | |||
Stage 1 Ripple | Dynamically changing operation mode (PFM-PWM-PFM) with load change. FFT plot before LDO with 4 MHz bandwidth, showing several frequency spikes as PFM frequency changes to PWM | Output ripple continues to be PWM as load changes, with minimal overshoot and undershoot at load step. FFT plot with 2.5 MHz bandwidth shows ripple at 1.5 MHz, as expected | Dynamically changing operation mode (PFM-PWM) with load change. FFT plot before PI filter with 4.25 MHz bandwidth, showing ripple primarily at very low frequencies (PFM) and switching frequency (1.8 MHz) |
Stage 2 Ripple | FFT plot after LDO with 4 MHz bandwidth shows higher overshoot and undershoot values (low frequency) and strong noise attenuation by LDO | N/A | FFT plot after PI filter with 4.25 MHz bandwidth, showing undershoot and overshoot present, though smaller than values in Architecture A, and very strong noise attenuation by PI filter |
Overshoot (at output of architecture) | 24 mV | 3 mV | 6 mV |
Overshoot Settling Time | 125 µs | 60 µs | 166 µs |
Undershoot (at output of architecture) | 76 mV | 3 mV | 8 mV |
Undershoot Settling Time | 129 µs | 29 µs | 96 µs |