ML7406 Family LSIs Hardware Design Manual
FEXL7406DG-01
2
*[1] The supply voltage for the PA_OUT pin (#20) should be provided the DC bias through the inductor
(L3).
*[2] The noise coming from the VDD_VCO pin (#32) will increases the phase noise level. The Adjacent
Channel Power Ratio (ACPR) and spurious performance may be improved by adjusting a resister value
(56Ω).
Notes the following when placing decoupling capacitors:
1. The VDD and GND traces should be wider than other signal line traces to reduce the resister element.
2. Decoupling capacitor should be placed as close to an LSI pin as possible.
3. The smaller capacitor should be closer to an LSI pin than other capacitors.
4. VDDIO (#9), VDD_PA (#22), VDD_REG (#1) pins connected to the VDD share the trace. and placing
a 10μF decoupling capacitor. A 10uF capacitor is recommended tantalum capacitor because it has low
leak current. If it doesn’t care leak current, any kind capacitor could be used.
5. A 10
µ
F decoupling capacitor should be placed to both the REG_OUT (#3) pin to stabilize 1.5V
regulator.
6. It is recommended to place a 1000 pF multilayer ceramic capacitor in parallel with a 10
µ
F tantalum
capacitor to both the REG_OUT (#3) pin
7. The VBG (#2) pin is a reference voltage output pin of band-gap reference circuit. Placing a 0.1μF
multilayer ceramic capacitor to the VBG (#2) pin to reduce the noise from the band-gap reference
circuit.
8. In general, ceramic capacitors have specific temperature and voltage characteristics. Select the best
capacitor for the operating voltage and temperature of your specific application. It is recommended that
decoupling capacitor use a CH (temperature compensating) or a B (high dielectric constant type) of
temperature characteristics.
9. ML7406 support low power consumption mode (SLEEP MODE). In this mode, the consumption current
of the LSI is around 0.9μA. Therefore the leak current of decoupling capacitors will impact on the
consumption current of your specific circuit. It is recommended to select the low leak current capacitor
to develop low consumption circuit board and system.