TEXAS INSTRUMENTS CD54HC297 Technical data

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CD54HC297, CD74HC297,

CD74HCT297

[ /Title
(CD74
HC297
,
CD74
HCT29

7)
Sub­ect

(High­Speed
CMOS
Logic
Digi­tal
Phase­Locked

Data sheet acquired from Harris Semiconductor
SCHS177B

November 1997 - Revised May 2003

Features

• Digital Design Avoids Analog Compensation Errors

• Easily Cascadable for Higher Order Loops

• Useful Frequency Range

- K-Clock . . . . . . . . . . . . . . . . . . . . . . . . . .DC to 55MHz (Typ)

- I/D-Clock . . . . . . . . . . . . . . . . . . . . DC to 35MHz (Typ)

• Dynamically Variable Bandwidth

• Very Narrow Bandwidth Attainable

• Power-On Reset

• Output Capability

- Standard. . . . . . . . . . . . . . . . . . . . XORPD

OUT

, ECPD

- Bus Driver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . I/D

• Fanout (Over Temperature Range)

- Standard Outputs . . . . . . . . . . . . . . . . . . 10 LSTTL Loads

- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads

• Balanced Propagation Delay and Transition Times

• Significant Power Reduction Compared to LSTTL
Logic ICs

• ’HC297 Types

- Operation Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . 2 to 6V

- High Noise ImmunityN

= 30%, NIH= 30% of VCC at 5V

IL

• CD74HCT297 Types

- Operation Voltage. . . . . . . . . . . . . . . . . . . . . . . . 4.5 to 5.5V

- Direct LSTTL Input Logic Compatibility

V

= 0.8V (Max), VIH= 2V (Min)

IL

- CMOS Input Compatibility I

≤ 1µA at VOL, V

I

OH

Pinout

CD54HC297

(CERDIP)

CD74HC297, CD74HCT29

(PDIP)

TOP VIEW

16
15
14
13
12
11
10

9

V

CC

C
D

φA

2

ECPD
XORPD

φB
φA

1

OUT

OUT

EN

I/D

CTR

K

I/D

OUT

GND

CP
CP

D/U

1

B

2

A

3
4
5
6
7
8

High-Speed CMOS Logic

Digital Phase-Locked Loop

Description

The ’HC297 and CD74HCT297 are high-speed silicon gate
CMOS devices that are pin-compatible with low power Schot­tky TTL (LSTTL).

These devices are designed to provide a simple, cost-effec­tive solution to high-accuracy,digital, phase-locked-loop appli­cations. They contain all the necessary circuits, with the
exception of the divide-by-N counter, to build first-order
phase-locked-loops.

Both EXCLUSIVE-OR (XORPD) and edge-controlled phase
detectors (ECPD) are provided for maximum flexibility . The
input signals for the EXCLUSIVE-OR phase detector must
have a 50% duty f actor to obtain the maximum loc k-range .

OUT

Proper partitioning of the loop function, with many of the build-

OUT

ing blocks external to the package, makes it easy for the
designer to incorporate ripple cancellation (see Figure 2) or to
cascade to higher order phase-locked-loops.

The length of the up/down K-counter is digitally programmable
according to the K-counter function table. With A, B, C and D
all LOW,the K-counter is disabled. With A HIGH and B, C and
D LOW,the K-counter is only three stages long, which widens
the bandwidth or capture range and shortens the lock time of
the loop. When A, B, C and D are all programmed HIGH, the
K-counter becomes seventeen stages long, which narrows
the bandwidth or capture range and lengthens the lock time.
Real-time control of loop bandwidth by manipulating the A to
D inputs can maximize the overall performance of the digital
phase-locked-loop .

The ’HC297 and CD74HCT297 can perform the classic first
order phase-locked-loop function without using analog com­ponents. The accuracy of the digital phase-locked-loop
(DPLL) is not affected by V
depends solely on accuracies of the K-clock and loop propa­gation delays.

Ordering Information

PART NUMBER TEMP. RANGE (oC) PACKAGE

CD54HC297F3A -55 to 125 16 Ld CERDIP
CD74HC297E -55 to 125 16 Ld PDIP
CD74HCT297E -55 to 125 16 Ld PDIP

and temperature variations but

CC

CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright

© 2003, Texas Instruments Incorporated

1

CD54HC297, CD74HC297, CD74HCT297CD54HC297, CD74HC297, CD74HCT297

The phase detector generates an error signal waveform that,
at zero phase error, is a 50% duty factor square wave. At the
limits of linear operation, the phase detector output will be
either HIGH or LOW all of the time depending on the direction
of the phase error (φIN - φOUT). Within these limits the phase
detector output varies linearly with the input phase error
according to the gain K

, which is expressed in terms of

d

phase detector output per cycle or phase error. The phase
detector output can be defined to vary between ±1 according
to the relation:

%HIGH - %LOW

phase detector output =

The output of the phase detector will be K
phase error φ

= φIN - φOUT.

e

--------------------------------------------

100

, where the

dφe

EXCLUSIVE-OR phase detectors (XORPD) and edge-con­trolled phase detectors (ECPD) are commonly used digital
types. The ECPD is more complex than the XORPD logic
function but can be described generally as a circuit that
changes states on one of the transitions of its inputs. The gain
(K

) for an XORPD is 4 because its output remains HIGH

d

(XORPD
Similarly, K

= 1) for a phase error of one quarter cycle.

OUT

for the ECPD is 2 since its output remains HIGH

d

for a phase error of one half cycle. The type of phase detector
will determine the zero-phase-error point, i.e., the phase sep­aration of the phase detector inputs for a φe defined to be
zero. For the basic DPLL system of Figure 3, φe = 0 when the
phase detector output is a square wave .

The XORPD inputs are one quarter cycle out-of-phase for
zero phase error. For the ECPD, φe = 0 when the inputs are
one half cycle out of phase.

The phase detector output controls the up/down input to the
K-counter. The counter is clocked by input frequency Mf
which is a multiple M of the loop center frequency fc. When
the K-counter recycles up, it generates a carry pulse. Recy­cling while counting down generates a borrow pulse. If the
carry and the borrow outputs are conceptually combined into
one output that is positive for a carry and negative for a bor­row , and if the K-counter is considered as a frequency divider
with the ratio Mf

/K, the output of the K-counter will equal the

c

input frequency multiplied by the division ratio. Thus the out­put from the K-counter is (K

dφeMfc

)/K.

The carry and borrow pulses go to the increment/decrement
(I/D) circuit which, in the absence of any carry or borrow
pulses has an output that is one half of the input clock (I/D

CP

The input clock is just a multiple, 2N, of the loop center fre­quency. In response to a carry of borrow pulse, the I/D circuit
will either add or delete a pulse at I/D
the I/D circuit will be Nf

+ (KdφeMfc)/2K.

c

. Thus the output of

OUT

The output of the N-counter (or the output of the phase­locked-loop) is thus: fo = fc + (KdφeMfc)/2KN.

If this result is compared to the equation for a first-order ana­log phase-locked-loop , the digital equivalent of the gain of the
VCO is just Mf

/2KN or fc/K for M = 2N.

c

Thus, the simple first-order phase-locked-loop with an adjust­able K-counter is the equivalent of an analog phase-locked­loop with a programmable VCO gain.

Functional Diagram

DCBA

14 15 1 2

4

K

CP

6

D/U

EN

CTR

I/D

CP

φA

1

φB

φA

2

φA

LL L
LH H
HL H
HH L

φA

H or L

↓

H or L ↑ No Change

↑ H or L No Change

H=Steady-State High Level,L= Steady-StateLowLevel, ↑=LOW
to HIGH φ Transition,↓ = HIGH to LOW φ Transition

c

DCBA

LLLLInhibited
LLLH2
LLHL2
LLHH2

).

LHLL2
LHLH2
LHHL2

LHHH2
HLLL2
HLLH2
HLHL2
HLHH2
HHLL2
HHLH2
HHHL2
HHHH2

MODULO-K

COUNTER

3

5
9

10
13

FUNCTION TABLE

EXCLUSIVE-OR PHASE DETECTOR

1

FUNCTION TABLE

EDGE-CONTROLLED PHASE DETECTOR

2

K-COUNTER FUNCTION TABLE

(DIGITAL CONTROL)

CARRY

BORROW

J

F/F

K

φB XORPD OUT

φB ECPD OUT

↓

H or L L

I/D

CKT

7

11

12

Q

I/D

OUT

XORPD

ECPD

H

MODULO

OUT

OUT

(K)

3
4
5
6
7
8

9
10
11
12
13
14
15
16
17

2

CD54HC297, CD74HC297, CD74HCT297CD54HC297, CD74HC297, CD74HCT297

Absolute Maximum Ratings Thermal Information

DC Supply Voltage, VCC. . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 7V

DC Input Diode Current, I

IK

For VI < -0.5V or VI > VCC + 0.5V. . . . . . . . . . . . . . . . . . . . . .±20mA

DC Output Diode Current, I

OK

For VO < -0.5V or VO > VCC + 0.5V . . . . . . . . . . . . . . . . . . . .±20mA

DC Drain Current, per Output, I

O

For -0.5V < VO < VCC + 0.5V. . . . . . . . . . . . . . . . . . . . . . . . . .±25mA

DC Output Source or Sink Current per Output Pin, I

O

For VO > -0.5V or VO < VCC + 0.5V . . . . . . . . . . . . . . . . . . . .±25mA

DC VCC or Ground Current, ICC . . . . . . . . . . . . . . . . . . . . . . . . .±50mA

Operating Conditions

Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC

Supply Voltage Range, V

HC Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2V to 6V

HCT Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.5V to 5.5V

DC Input or Output Voltage, VI, VO . . . . . . . . . . . . . . . . . 0V to V

Input Rise and Fall Time

2V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000ns (Max)

4.5V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500ns (Max)

6V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400ns (Max)

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

NOTE:

1. The package thermal impedance is calculated in accordance with JESD 51-7.

CC

Thermal Resistance (Typical, Note 1) θJA (oC/W)

E (PDIP) Package . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Maximum Junction Temperature. . . . . . . . . . . . . . . . . . . . . . . 150oC

Maximum Storage Temperature Range . . . . . . . . . .-65oC to 150oC

Maximum Lead Temperature (Soldering 10s). . . . . . . . . . . . . 300oC

CC

DC Electrical Specifications

PARAMETER SYMBOL

HC TYPES

High Level Input
Voltage

Low Level Input
Voltage

High Level Output
Voltage
CMOS Loads

High Level Output
Voltage
TTL Loads

Low Level Output
Voltage
CMOS Loads

Low Level Output
Voltage
TTL Loads

V

IH

V

IL

V

OH

V

OL

TEST

CONDITIONS

25oC -40oC TO 85oC -55oC TO 125oC

VCC (V)

- - 2 1.5 - - 1.5 - 1.5 - V

4.5 3.15 - - 3.15 - 3.15 - V
6 4.2 - - 4.2 - 4.2 - V

- - 2 - - 0.5 - 0.5 - 0.5 V

4.5 - - 1.35 - 1.35 - 1.35 V
6 - - 1.8 - 1.8 - 1.8 V

VIH or

V

-0.02 2 1.9 - - 1.9 - 1.9 - V

IL

-0.02 4.5 4.4 - - 4.4 - 4.4 - V

-0.02 6 5.9 - - 5.9 - 5.9 - V

-6

4.5 3.98 - - 3.84 - 3.7 - V

(Note 2)

-7.8

6 5.48 - - 5.34 - 5.2 - V

(Note 2)

VIH or

V

0.02 2 - - 0.1 - 0.1 - 0.1 V

IL

0.02 4.5 - - 0.1 - 0.1 - 0.1 V

0.02 6 - - 0.1 - 0.1 - 0.1 V
4

4.5 - - 0.26 - 0.33 - 0.4 V

(Note 2)

5.2

6 - - 0.26 - 0.33 - 0.4 V

(Note 2)

UNITSVI(V) IO(mA) MIN TYP MAX MIN MAX MIN MAX

3

CD54HC297, CD74HC297, CD74HCT297CD54HC297, CD74HC297, CD74HCT297

DC Electrical Specifications (Continued)

TEST

CONDITIONS

PARAMETER SYMBOL

Input Leakage
Current

Quiescent Device
Current

I

I

CC

VCC or

I

GND

VCC or

GND

VCC (V)

-6--±0.1 - ±1-±1 µA

0 6 - - 8 - 80 - 160 µA

HCT TYPES

High Level Input
Voltage

Low Level Input
Voltage

High Level Output
Voltage

V

IH

- - 4.5 to

5.5

V

IL

- - 4.5 to

5.5

V

OH

VIH or

V

IL

-0.02 4.5 4.4 - - 4.4 - 4.4 - V

CMOS Loads
High Level Output

-4 4.5 3.98 - - 3.84 - 3.7 - V
Voltage
TTL Loads

Low Level Output
Voltage

V

OL

VIH or

V

IL

0.02 4.5 - - 0.1 - 0.1 - 0.1 V

CMOS Loads
Low Level Output

4 4.5 - - 0.26 - 0.33 - 0.4 V
Voltage
TTL Loads

Input Leakage
Current

Quiescent Device
Current

Additional Quiescent
Device Current Per

I

I

I

CC

∆I

CC

(Note 2)

VCC to

GND

VCC or

GND

V

CC

-2.1

0 5.5 - - ±0.1 - ±1-±1 µA

0 5.5 - - 8 - 80 - 160 µA

- 4.5 to

5.5

Input Pin: 1 Unit Load

NOTE:

2. For dual-supply systems theoretical worst case (VI = 2.4V, VCC = 5.5V) specification is 1.8mA.

25oC -40oC TO 85oC -55oC TO 125oC

2-- 2 - 2 - V

- - 0.8 - 0.8 - 0.8 V

- 100 360 - 450 - 490 µA

UNITSVI(V) IO(mA) MIN TYP MAX MIN MAX MIN MAX

HCT Input Loading Table

INPUT UNIT LOADS

EN

, D/U 0.3

CTR

A, B, C, D, KCP, φA

2

I/DCP, φA1, φB 1.5

NOTE: Unit Load is ∆ICClimit specified in DC Electrical
Specifications table, e.g., 360µA max at 25oC.

0.6

4

CD54HC297, CD74HC297, CD74HCT297CD54HC297, CD74HC297, CD74HCT297

Prerequisite For Switching Function

PARAMETER SYMBOL VCC (V)

HC TYPES

Maximum Clock Frequency
K

CP

Maximum Clock Frequency
I/D

CP

Clock Pulse Width
K

CP

Clock Pulse Width
I/D

CP

Set-up Time
D/U, EN

CTR

to K

CP

Hold Time
D/U, EN

CTR

to K

CP

HCT TYPES

Maximum Clock Frequency
K

CP

Maximum Clock Frequency
I/D

CP

Clock Pulse Width
K

CP

Clock Pulse Width
I/D

CP

Set-up Time
D/U, EN

CTR

to K

CP

Hold Time
D/U, EN

CTR

to K

CP

f

MAX

f

MAX

t

t

f

MAX

f

MAX

t

t

W

SU

t

t

t

SU

t

w

H

w

w

H

25oC -40oC TO 85oC -55oC TO 125oC

UNITSMIN MAX MIN MAX MIN MAX

26-5-4-MHz

4.5 30 - 24 - 20 - MHz
6 35 - 28 - 24 - MHz
24-3-2-MHz

4.5 20 - 16 - 13 - MHz
6 24 - 19 - 15 - MHz
2 80 - 100 - 120 - ns

4.5 16 - 20 - 24 - ns
614-17-20-ns
2 125 - 155 - 190 - ns

4.5 25 - 31 - 38 - ns
621-26-32-ns
2 100 - 125 - 150 - ns

4.5 20 - 25 - 30 - ns
617-21-26-ns
20-0-0-ns

4.50-0-0-ns
60-0-0-ns

4.5 30 - 24 - 20 - MHz

4.5 20 - 16 - 13 - MHz

4.5 16 - 20 - 24 - ns

4.5 25 - 31 - 38 - ns

4.5 20 - 25 - 30 - ns

4.50-0-0-ns

Switching Specifications Input t

PARAMETER SYMBOL

HC TYPES

Propagation Delay,
I/DCP to I/D

OUT

t

PLH

, t

, tf = 6ns

r

TEST

CONDITIONS VCC (V)

PHLCL

= 50pF 2 - 175 220 265 ns

25oC -40oC TO 85oC -55oC TO 125oC

UNITSTYP MAX MAX MAX

4.5 - 35 44 53 ns
6 - 30 34 43 ns

5