ADSP-2104KP-80 View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

ADSP-2104KP-80

Low Cost DSP Microcomputers

Analog Devices 

ADSP-2104/ADSP-2109

SPECIFICATIONS (ADSP-2104/ADSP-2109)

POWER DISSIPATION EXAMPLE

To determine total power dissipation in a specific application,

the following equation should be applied for each output:

C × VDD2 × f

C = load capacitance, f = output switching frequency.

Example:

In an ADSP-2104 application where external data memory is

used and no other outputs are active, power dissipation is

calculated as follows:

Assumptions:

• External data memory is accessed every cycle with 50% of the

address pins switching.

• External data memory writes occur every other cycle with

50% of the data pins switching.

• Each address and data pin has a 10 pF total load at the pin.

• The application operates at VDD = 5.0 V and tCK = 50 ns.

Total Power Dissipation = PINT + (C × VDD2 × f )

PINT = internal power dissipation (from Figure 7).

(C × VDD2 × f ) is calculated for each output:

Output

# of

Pins ؋ C

؋ VDD2 × f

Address, DMS 8

Data, WR

9

RD

1

CLKOUT 1

× 10 pF

× 10 pF

× 10 pF

× 10 pF

× 52 V

× 52 V

× 52 V

× 52 V

× 20 MHz = 40.0 mW

× 10 MHz = 22.5 mW

× 10 MHz = 2.5 mW

× 20 MHz = 5.0 mW

70.0 mW

Total power dissipation for this example = PINT + 70.0 mW.

ENVIRONMENTAL CONDITIONS

Ambient Temperature Rating:

TAMB = TCASE – (PD × θCA)

TCASE = Case Temperature in °C

PD = Power Dissipation in W

θCA = Thermal Resistance (Case-to-Ambient)

θJA = Thermal Resistance (Junction-to-Ambient)

θJC = Thermal Resistance (Junction-to-Case)

CAPACITIVE LOADING

Figures 8 and 9 show capacitive loading characteristics.

8

7

VDD = 4.5V

6

5

4

3

2

1

0

0 25 50 75 100 125 150 175

CL – pF

Figure 8. Typical Output Rise Time vs. Load Capacitance, CL

(at Maximum Ambient Operating Temperature)

5

4

3

VDD = 4.5V

2

1

0

–1

–2

–3

0 25 50 75 100 125 150 175

CL – pF

Figure 9. Typical Output Valid Delay or Hold vs. Load

Capacitance, CL (at Maximum Ambient Operating Temperature)

Package

PLCC

␪JA

27°C/W

␪JC

16°C/W

␪CA

11°C/W

–14–

REV. 0

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