LV5680P Datasheet, PDF (10/13 Pages) Sanyo Semicon Device – For Car Audio Systems Multi-Power Supply System IC

LV5680P
• ILM output voltage setting method
Formula for ILM voltage calculation
Z₁
=
R₂ //R₃
=
R₂ ⋅ R₃
R₂ + R₃
1 ^ILM
R2 59.67kΩ
R3
ILM_F
2
1.26V
Z1=R2/R3
R1 7kΩ
The ILM_F voltage is determined by the
internal band gap voltage of the IC (typ = 1.26V).
ILM
=
1.26[V
R₁
]
×
Z₁
+1.26[V ]
Z₁
=
(ILM
−1.26)⋅
1.26
R₁
R₃
=
R₂ ⋅ Z₁
R₂ − Z₁
Example : ILM = 9V setting method
Z₁
=
(9V
−1.26V )⋅ 7kΩ
1.26V
≅
43kΩ
When R3 = 150k, the ILM output voltage will be as follows:
Z₁^′
=
59.67kΩ ⋅150kΩ
59.67kΩ +150kΩ
≅
42.69kΩ
ILM = ^1.26V × 42.69kΩ +1.26V ≅ 8.94V
7kΩ
• AUDIO output voltage setting method
AUDIO
5
R1
AUDIO_F
4
1.26V
R2
The AUDIO_F voltage is determined by the
internal band gap voltage of the IC (typ = 1.26V).
Formula for AUDIO voltage calculation
AUDIO
=
1.26[V
R₂
]
×
R₁
+
1.26[V
]
R_{1 =} (AUDIO −1.26)
R₂
1.26
The circuit must be designed in such a way that the R1:R2 ratio
satisfies the formula given above for the AUDIO voltage that
has been set.
Example : AUDIO = 8.5V setting method
R_{1 =} (8.5 −1.26) _{≅ 5.75}
R₂
1.26
R_{1 =} 27kΩ _{≅ 5.74}
R₂ 4.7kΩ
AUDIO = 1.26V × 5.74 +1.26V ≅ 8.49V
Note : In the above, the typical values are given in all instances for the values used and, as such, they will vary due to the
effects of production-related variations of the IC and external resistors.
No.A1764-10/13