SLUSFH4A March 2025 – July 2025 BQ25858-Q1 , BQ25858B-Q1
PRODUCTION DATA
請參考 PDF 數據表獲取器件具體的封裝圖。
The device integrates all the loop compensation, thereby providing a high density solution with ease of use.
The power converter employs a synchronous buck-boost converter that allows converter operation from a wide range of input voltage sources. The converter operates in buck, buck-boost or boost mode. The converter can operate uninterruptedly and continuously across the three operation modes. During buck-boost mode, the converter alternates a SW1 pulse with a SW2 pulse, with effective switching frequency interleaved among these pulses for highest efficiency operation.
During boost mode operation, the HS FET is forced to turn on for 225ns in each switching cycle to ensure inductor energy is delivered to the output, effectively limiting the maximum boosting ratio. For example, when device is configured to switch at 500kHz, the switching period is 2μs, yielding a duty cycle limit of (1 - 0.225μs/2μs) = 88.75%. Given a 5V input, this translates to a maximum 44V output assuming 100% efficiency. The true output will be lower than this ideal limit. At lower switching frequencies, the maximum duty cycle increases, making the limitation less significant.
| MODE | BUCK | BUCK-BOOST | BOOST |
|---|---|---|---|
| HS BUCK FET | Switching at fSW | Switching (fSW interleaved between SW1 and SW2) | ON |
| LS BUCK FET | Switching at fSW | Switching (fSW interleaved between SW1 and SW2) | OFF |
| LS BOOST FET | OFF | Switching (fSW interleaved between SW1 and SW2) | Switching at fSW |
| HS BOOST FET | ON | Switching (fSW interleaved between SW1 and SW2) | Switching at fSW |