ST7565
( ) V5 =
1+
Rb
Ra
VEV
( ) ( ) =
1+
Rb
Ra
1-
α
162
VREG
[ ( ) ] ∵ VEV =
1-
α
162
VREG
Internal Ra
VDD
VEV(constant voltage supply+electronic volume)
V5
Internal Rb
Figure 8
VREG is the IC-internal fixed voltage supply, and its voltage at Ta = 25°C is as shown in Table 9.
Part no.
ST7565-0A
ST7565-0B
Table 9
Equipment Type
(1) Internal Power Supply
(2) External Input
Thermal Gradient
–0.15 %/°C
—
VREG
–2.1V
VRS
α is set to 1 level of 64 possible levels by the electronic volume function depending on the data set in the 6-bit electronic
volume register. Table 10 shows the value for α depending on the electronic volume register settings.
Rb/Ra is the V5 voltage regulator internal resistor ratio, and can be set to 8 different levels through the V5 voltage regulator
internal resistor ratio set command. The (1 + Rb/Ra) ratio assumes the values shown in Table 11 depending on the 3-bit data
settings in the V5 voltage regulator internal resistor ratio register.
Table 10
D5 D4 D3 D2 D1 D0 α
0 0 0 0 0 0 63
0 0 0 0 0 1 62
0 0 0 0 1 0 61
:
:
:
:
1 11 10 1 2
1 11 11 0 1
1 11 11 1 0
Ver 1.0a
22/56
2002/06/24