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ZHCSJ97B September 2009 – January 2019 TPS60151

PRODUCTION DATA.

封装选项

机械数据 (封装 | 引脚)

DRV|6
- MPDS216E

散热焊盘机械数据 (封装 | 引脚)

DRV|6
- QFND087M

订购信息

9.2.2.1 Capacitor Selection

For minimum output voltage ripple, the output capacitor (C_OUT) should be a surface-mount ceramic capacitor. Tantalum capacitors generally have a higher effective series resistance (ESR) and may contribute to higher output voltage ripple. Leaded capacitors also increase ripple due to the higher inductance of the package itself. To achieve the best operation with low input voltage and high load current, the input and flying capacitors (C_IN and C_FLY, respectively) should also be surface-mount ceramic types.

Figure 11. Capacitors

Generally, C_FLY can be calculated by the following simple equation,

Equation 2. TPS60151 eq_qchg_lvs888.gif

Both equation should be same, TPS60151 eq_inline_lvs888.gif

Equation 3. TPS60151 eq_cfly_lvs888.gif

If I_LOAD = 140 mA, f = 1.5 MHz, and ΔV_CFLY = 100 mV, the minimum value of the flying capacitor should be 1 μF.

Output capacitance, C_OUT, is also strongly related to output ripple voltage and loop stability,

Equation 4. TPS60151 eq_ripple_lvs888.gif

The minimum output capacitance for all output levels is 2.2 μF due to control stability. Larger ceramic capacitors or low ESR capacitors can be used to lower the output ripple voltage.

Table 1. Suggested Capacitors (Input / Output / Flying Capacitor)

VALUE	DIELECTRIC MATERIAL	PACKAGE SIZE	RATED VOLTAGE
4.7 μF	X5R or X7R	0603	10 V
2.2 μF	X5R or X7R	0603	10 V

The efficiency of the charge pump regulator varies with the output voltage, the applied input voltage and the load current.

The approximate efficiency in normal operating mode is given by:

Equation 5. TPS60151 eq_eff_lvs888.gif

Equation 6. TPS60151 eq_eff2_lvs888.gif