Focus Enhancements FS454 データシート

 

Video Outputs 
DAC_A A8 

68 

analog 

video 

Video output.  As programmed by the 
DAC_CNTL (9Eh) register.  

DAC_B A7 

70 

analog 

video 

Video output.  As programmed by the 
DAC_CNTL (9Eh) register.  

DAC_C A6 

72 

analog 

video 

Video output.  As programmed by the 
DAC_CNTL (9Eh) register.  

DAC_D A9 

66 

analog 

video 

Video output.  As programmed by the 
DAC_CNTL (9Eh) register.  

Voltage Reference 
RSVD1  

76 

  Reserved.  Not internally connected.  

 

FS_ADJ B3 

78 

549

Ω or 

1.1k

Ω 

Full Scale Adjust.  A resistor connected 
between FS_ADJ and ground sets the current 
range of the D/A converters.  Use 549

Ω for a 

37.5

Ω load (common) or 1.1kΩ for a 75Ω load.  

Note that there is a 75 Ohm terminating 
resistor in consumer televisions. 

COMP B4 

75 

0.1 

µF 

Compensation.  A 0.1µF capacitor must be 
connected between COMP and VDD_DA. 

VBIAS A4 

77 

100

Ω/0.1µF 

Voltage Bias Decoupling.  An optional series 
100

Ω/0.1µF capacitor can be connected 

between VBIAS and VDD_DA to reduce noise 
at the D/A outputs.  Otherwise, leave 
disconnected.   

Serial Port 
ALT_ADDR H13  48 

TTL 

input 

(internal pull 
down) 

Serial data address select.  Selects the 7-bit 
serial bus address: 
ALT_ADDR = H: 0x6A 
ALT_ADDR = L: 0x4A 

SDATA K13 

44 

TTL 

I/0 

(open drain) 

Serial data.  Data line of the serial port.  
Connect to GCC serial data pin. 

SCLK K12 

45 

TTL 

Input 

Serial clock.  Clock line of the serial port.  
Connect to GCC serial clock pin. 

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