DS0025CN [NSC]

Two Phase MOS Clock Driver; 两相MOS时钟驱动器


型号：	DS0025CN
厂家：	National Semiconductor
描述：	Two Phase MOS Clock Driver 两相MOS时钟驱动器时钟驱动器
文件：	总6页 (文件大小：148K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

June 1992

DS0025C Two Phase MOS Clock Driver

General Description

Features

8-lead TO-5 or 8-lead or 14-lead dual-in-line package

High Output Voltage SwingsÐup to 25V

The DS0025C is a monolithic, low cost, two phase MOS

clock driver that is designed to be driven by TTL line drivers

or buffers such as the DS8830 or DM7440. Two input cou-

pling capacitors are used to perform the level shift from TTL

to MOS logic levels. Optimum performance in turn-off delay

and fall time are obtained when the output pulse is logically

controlled by the input. However, output pulse width may be

set by selection of the input capacitor eliminating the need

for tight input pulse control.

High Output Current Drive CapabilityÐup to 1.5A

Rep. Rate: 1.0 MHz into

1000 pF

Driven by DS8830, DM7440

‘‘Zero’’ Quiescent Power

Connection Diagrams

Metal Can Package

Dual-In-Line Package

TL/F/5852–1

Note: Pin 4 connected to case.

Top View

Order Number DS0025CH

See NS Package Number H08C

TL/F/5852–2

Top View

Order Number DS0025CJ-8

or DS0025CN

See NS Package Number J08A or N08E

Dual-In-Line Package

TL/F/5852–3

Top View

Order Number DS0025CJ

See NS Package Number J14A

1995 National Semiconductor Corporation

TL/F/5852

RRD-B30M105/Printed in U. S. A.

Absolute Maximum Ratings (Note 1)

Recommended Operating

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales

Office/Distributors for availability and specifications.

Conditions

V^aV^bDifferential Voltage

Min

20V

Max

(V^a

^b)Voltage Differential

25V

100 mA

1.5A

Temperature

Input Current

Maximum Power Dissipation* at 25 C

Peak Output Current

8-Pin Cavity Package

14-Pin Cavity Package

Molded Package

1150 mW

1410 mW

1080 mW

670 mW

65 C to 150 C

Storage Temperature

Operating Temperature

Lead Temperature (Soldering, 10 sec)

0 C to 85 C

Metal Can (TO-5) Package

300 C

* Derate 8-pin cavity package 7.8 mW/ C above 25 C; de-

rate 14-pin cavity package 9.5 mW/ C above 25 C; derate

molded package 8.7 mW/ C above 25 C; derate metal

can (TO-5) package 4.5 mW/ C above 25 C.

Electrical Characteristics (Notes 2 and 3) See test circuit.

Symbol

Parameter

Turn-On Delay Time

Rise Time

Conditions

Min

Typ

Max

Units

0.001 mF, R

0X, C

0.001 mF

d ON

RISE

d OFF

Turn-Off Delay Time

(Note 4)

Fall Time

0.001 mF, R

0X,

(Note 4)

(Note 5)

120

250

FALL

0.001 mF

100

150

500

0.001 mF, R

Pulse Width (50% to 50%)

0.001 mF (Note 5)

Positive Output Voltage Swing

Negative Output Voltage Swing

0V, I

OUT

1 mA

V^a1.0 V^a0.7V

e b

10 mA, I

V^b0.7V V^b1.5V

a a

OUT

Note 1: ‘‘Absolute Maximum Ratings’’ are those values beyond which the safety of the device cannot be guaranteed. Except for ‘‘Operating Temperature Range’’

they are not meant to imply that the devices should be operated at these limits. The table of ‘‘Electrical Characteristics’’ provides conditions for actual device

operation.

Note 2: Unless otherwise specified min/max limits apply across the 0 C to 70 C range for the DS0025C.

Note 3: All currents into device pins shown as positive, out of device pins as negative, all voltages referenced to ground unless otherwise noted. All values shown

as max or min on absolute value basis.

Note 4: Parameter values apply for clock pulse width determined by input pulse width.

Note 5: Parameter values for input width greater than output clock pulse width.

Timing Diagram

Input waveform:

PRR 0.5 MHz

5.0V

P-P

10 ns

Pulse width:

A. 1.0 ms

B. 200 ns

TL/F/5852–5

Typical Application

TL/F/5852–4

AC Test Circuit

TL/F/5852–6

*Q1 is selected high speed NPN switching transistor.

Typical Performance

Transient Power vs Rep. Rate

DC Power (P ) vs Duty Cycle

TL/F/5852–8

DUTY CYCLE (%)

) (DC)

TL/F/5852–7

V^a–V^b

(V^a–V^b) fC

Maximum Load Capacitance

Output PW Controlled by C

TL/F/5852–10

TL/F/5852–9

Peak Current delivered by driver

0.6

MAX

) (1k)–(V^a

(f) (1k) (V^a

)

(DC)

(I ) (t )

MAX

)

V^a

MIN

Applications Information

Circuit Operation

Transient Output Power

Input current forced into the base of Q through the cou-

pling capacitor C causes Q to be driven into saturation,

The average transient power (P ) dissipated, is equal to

the energy needed to charge and discharge the output ca-

swinging the output to V^b

(sat)

Diode

pacitive load (C ) multiplied by the frequency of operation

(f).

When the input current has decayed, or has been switched,

such that Q turns off, Q receives base drive through R ,

turning Q on. This supplies current to the load and the

)

x (V^a–V^b

x f

(2)

For V^a

400 mW.

Internal Power

20V, f

1.0 MHz, C

1000 pF, P

output swings positive to V^a–V

Negligible ( 3 mW)

‘‘0’’ State

‘‘1’’ State

(V^a–V^b

)

int

x Duty Cycle

(3)

80 mW for V^a–V^b

20V, DC

20%

Package Power Dissipation

internal

Total average power

power.

transient output power

Example Calculation

How many MM506 shift registers can be driven by

TL/F/5852–11

DS0025CN driver at 1 MHz using a clock pulse width of 200

ns, rise time 30–50 ns and 16V amplitude over the tempera-

ture range 0 –70 C?

FIGURE 1. DS0025 Schematic (One-Half Circuit)

It may be noted that Q must switch off before Q begins to

supply current, hence high internal transients currents from

V^bto V^acannot occur.

Power Dissipation:

At 70 C the DS0025CN can dissipate 870 mW when sol-

dered into printed circuit board.

Fan-Out Calculation

The drive capability of the DS0025 is a function of system

requirements, i.e. speed, ambient temperature, voltage

swing, drive circuitry, and stray wiring capacity.

Transient Peak Current Limitation:

From equation (1), it can be seen that at 16V and 30 ns, the

maximum load that can be driven is limited to 2800 pF.

The following equations cover the necessary calculations to

enable the fan-out to be calculated for any system condi-

tion.

Average Internal Power:

Equation (3), gives an average power of 50 mW at 16V and

a 20% duty cycle.

Transient Current

The maximum peak output current of the DS0025 is given

as 1.5A. Average transient current required from the driver

can be calculated from:

For one-half of the DS0025C, 870 mW

ed.

2 can be dissipat-

transient output power.

435 mW

385 mW

50 mW

(V^a–V^b

)

transient output power.

(1)

Using equation (2) at 16V, 1 MHz and 350 mW, each half of

the DS0025CN can drive a 1367 pF load. This is less than

the load imposed by the transient current limitation of equa-

tion (1) and so a maximum load of 1367 pF would prevail.

Typical rise times into 1000 pF load is 25 ns. For V^a

0.8A.

20V, I

From the data sheet for the MM506, the average clock

pulse load is 80 pF. Therefore the number of devices driven

is 1367/80 or 17 registers.

For further information please refer to National Semicon-

ductors Application Note AN-76.

Physical Dimensions inches (millimeters)

Order Number DS0025CH

NS Package Number H08C

Order Number DS0025CJ

NS Package Number J08A

Physical Dimensions inches (millimeters) (Continued)

Order Number DS0025CJ

NS Package Number J14A

Order Number DS0025CN

NS Package Number N08E

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support device or system whose failure to perform can

be reasonably expected to cause the failure of the life

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