EVALPM6680A STMicroelectronics, EVALPM6680A Datasheet - Page 23

• Manufacturer Part Number: EVALPM6680A
• Description: EVAL BOARD FOR PM6680A
• Manufacturer: STMicroelectronics

Specifications of EVALPM6680A

• Mfg Application Notes: PM6680A, AN2565 Appl Note
• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 3, Non-Isolated
• Power - Output: 10.5W
• Voltage - Output: 1.8V, 3.3V, 5V
• Current - Output: 2.5A, 2.5A, 100mA
• Voltage - Input: 6 ~ 36V
• Regulator Topology: Buck
• Frequency - Switching: 200kHz, 300kHz
• Board Type: Fully Populated
• Utilized Ic / Part: PM6680A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6263

PM6680A
7.5
No-audible skip mode
If SKIP pin is tied to V
33 kHz is enabled. At light load condition, If there is not a new switching cycle within a 30 µs
(typ.) period, a no-audible skip mode cycle begins.
Figure 32. No audible skip mode
The low side switch is turned on until the output voltage crosses about Vreg + 1 %. Then the
high side MOSFET is turned on for a fixed on time period. Afterwards the low side switch is
enabled until the inductor current reaches the zero-crossing threshold. This keeps the
switching frequency higher than 33 kHz. As a consequence of the control, the regulated
voltage can be slightly higher than Vreg (up to 1 % ).
If, due to the load, the frequency is higher than 33 kHz, the device works like in skip mode.
No-audible skip mode reduces audio frequency noise that may occur in pulse skip mode at
very light loads, keeping the efficiency higher than in PWM mode.
REF
, a no-audible skip mode with a minimum switching frequency of
µ
Device description
23/48