TDA8752A Datasheet, PDF (19/36 Pages) NXP Semiconductors – Triple high-speed Analog-to-Digital Converter ADC

Philips Semiconductors
Triple high-speed Analog-to-Digital
Converter (ADC)
Product specification
TDA8752A
Table 5 Charge-pump current control
Ip2
Ip1
Ip0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
CURRENT
(µA)
6.25
12.5
25
50
100
200
400
700
The default programmed value is as follows:
• Charge pump current = 100 µA
• Test bits: no test mode; bits Up and Do at logic 0
• Rising edge of CKREF: bit edge at logic 0
• COAST and HSYNC inputs are active HIGH: V level and
H level at logic 0.
VCO REGISTER
The bits Z2, Z1 and Z0 enable the internal resistance for
the VCO filter to be selected.
Table 6 VCO register bits
Z2
Z1
Z0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
RESISTANCE
(kΩ)
high impedance
128
32
16
8
4
2
1
Table 7 VCO gain control
V_CO1
1
0
1
1
V_CO0
0
1
0
1
VCO gain
(MHz/V)
60
30
60
100
PIXEL CLOCK
FREQUENCY
RANGE (MHz)
10 to 17
17 to 35
35 to 60
60 to 100
The bits V_CO1 and V_CO0 control the VCO gain.
The default programmed value is as follows:
• Internal resistance = 16 kΩ
• VCO gain = 15 MHz/V.
DIVIDER REGISTER
This register controls the PLL frequency. The bits are the
LSB bits.
The default programmed value is 0011 0010 0000 = 800.
The MSB bits (Di11, Di10 and Di9) and the LSB bit (Di0)
have to be programmed before the bits Di8 to Di1 to have
the required divider ratio. The bit Di0 is used for the parity
divider number = Di0 = 0 = even number Di0 = 1 = odd
number. It should be noted that if the I²C-bus programming
is done in mode = 1 and the bit Di0 has to be toggled, then
the registers have to be loaded twice to have the update
divider ratio.
POWER-DOWN MODE
• When the supply is completely switched off, the
registers are set to their default values; in that event they
have to be reprogrammed if the required settings are
different (e.g. through an EEPROM)
• When the device is in power-down mode, the previously
programmed register values remain unaffected.
PHASEA AND PHASEB REGISTERS
The bit Cka is logic 0 when the used clock is the PLL clock,
and logic 1 when the used clock is the external clock.
The bit Ckb is logic 0 when the second clock is not used.
The bits Pa4 to Pa0 and Pb4 to Pb0 are used to program
the phase shift for the clock, CKADCO, CKAO and CKBO
(see Table 8).
1999 Feb 24
19