TDA3663 Datasheet, PDF (6/15 Pages) NXP Semiconductors – Very low dropout voltage/quiescent current 3.3 V voltage regulator

NXP Semiconductors
TDA3663
Very low dropout voltage/quiescent current 3.3 V voltage regulator
11. Application information
11.1 Noise
The output noise is determined by the value of the output capacitor. The noise figure is
measured at a bandwidth of 10 Hz to 100 kHz (see Table 7).
Table 7: Noise figures
Output current I_REG (mA)
0.5
50
Noise figure (µV)
C2 = 10 µF
550
650
C2 = 47 µF
320
400
C2 = 100 µF
300
400
11.2 Stability
For stable operation:
• The maximum output capacitor ESR should not exceed 22 Ω (worst-case) and for the
minimum ESR, see Table 8.
• The ESR of the output capacitor is limited.
• See Table 8 for the minimum ESR values of the output capacitor, at T_amb given the
load and output capacitance.
Remark: In the event of using different types of capacitors, a minimum ESR needs to
be created by using an additional resistor that is placed is series with the output
capacitor, see Figure 4.
• It is recommended not to use below 1 mA output current because of reduced phase
margin.
Table 8: Minimum ESR values required
I_REG (mA) max C2 = 100 nF
1
>0Ω
C2 = 1 µF
> 1.5 Ω
5
>1Ω
> 0.5 Ω
10
>0Ω
> 0.5 Ω
100
>0Ω
> 0.5 Ω
C2 = 10 µF
> 2.5 Ω
>1Ω
>4Ω
>4Ω
C2 = 100 µF
>0Ω
>0Ω
>0Ω
>0Ω
11.3 Application circuits
The maximum output current of the regulator equals:
I _REG(max) = -_R---_t--_h---₍--_j--_–---¹-_a--⁵₎---⁰_×-----^–₍---_V-^T---_P-^a---^m_–---^b--_V----_R---_E---_G----₎ = ₁----₀---₀₁---⁵-_×--⁰---₍--^–_V----^T-_P---^a-_–--^m--₃-^b--_.--₃----₎₍mA)
When T_amb = 21 °C and V_P = 14 V the maximum output current equals 116 mA.
The total thermal resistance of the TDA3663 can be decreased from 155 K/W to 30 K/W
for the SO8 version. For the SO4 version it can be decreased from 100 K/W to 25 K/W
when GND pins 2 and 4 of the package are soldered to the printed-circuit board.
TDA3663_6
Product data sheet
Rev. 06 — 26 June 2007
© NXP B.V. 2007. All rights reserved.
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