Datasheet SCL5616HW Datasheet (Allegro MicroSystems)

5616

2-FUNCTION, 4-DIGIT LCD AUTOMOTIVE CLOCK

5616

2-FUNCTION, 4-DIGIT

LCD AUTOMOTIVE CLOCK—PROGRAMMABLE

The SCL5616HW is a 2-function digital automotive clock circuit.
Fabricated on a single monolithic chip using silicon-gate CMOS PROM
technology, it offers low cost, low power, and high reliability. It also

f2

a2

g2

b1

PM

AM

BACKPLANE

adge1

includes digital frequency correction, stored in the internal nonvolatile
memory, for easy adjustment of the oscillator nominal frequency.

Data Sheet

26110

b2

COLON

g3

ad3

b3
g4

a4

S2

SELECT

GROUND

c1
e2
d2

f3

2040 x 3040 µm

0.080 x 0.120 in

f4

DD

V

IGNITION

NU

PP

NU

V

GROUND

Dwg. No. PC-001

c2
e3

c3
e4

d4
c4
b4
S1
DATA

{

OSC.

The SCL5616HW is supplied in wafer form and is rated for
continuous operation over the automotive temperature range of

-40°C to +85°C.

FEATURES

■ Digital Tuning of Crystal Frequency

■ PROM for Storing Frequency Correction Information

■ 12 or 24 Hour Timekeeping Option

■ Flashing Colon

■ Two Switches Control All Setting Functions

■ High Noise Immunity

■ Internal Power-Up Reset Circuitry

■ Internal Voltage Regulation

ABSOLUTE MAXIMUM RATINGS

Supply Current, IDD.......................... 2.0 mA

Input Voltage Range, V

(except VPP)......................-0.3 V to V

(Programming
Power Voltage, V

Input Current (except V

DISCONTINUED PRODUCT

Power Dissipation, PD................... 300 mW

Operating Temperature Range,

.................................. -40°C to +85°C

T

A

Storage Temperature Range,

T

S

— FOR REFERENCE ONLY

................................-65°C to +150°C

IN

) .................. 18.5 V

PP

), IIN......... ±10 mA

PP

DD

Caution: These CMOS devices have static pro­tection, but are susceptible to damage if exposed
to extremely high static electrical charges.

Always order by complete part number: SCL5616HW .

5616

Ω

S

L

2-FUNCTION, 4-DIGIT LCD AUTOMOTIVE CLOCK

TYPICAL APPLICATION

+12 V

6.8 kΩ

1 MΩ

MINUTES

HOURS

4.194304 MHz

C = 15 pF, R = 50

IGNITION

S2

S1

GROUNDS

+

47 µF

V

DD

SEGMENTS

BACKPLANE

A M
P M

Dwg. EC-001

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

W
Copyright © 1990, 1995, Allegro MicroSystems, Inc.

5616

2-FUNCTION, 4-DIGIT LCD AUTOMOTIVE CLOCK

ELECTRICAL CHARACTERISTICS at T
(unless otherwise noted).

= -40°C to +85°C, in Typical Application

A

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Operating Voltage Range V
Zener Voltage V
Segment Output Current I

Backplane Output Current I

LCD Drive Signal V
Input Current I
Oscillator Frequency f
Oscillator Starting Time t
Oscillator Stability ∆f
Backplane Frequency f
Switch Debounce Time t
Osc. Feedback Resistance R
Osc. Input Capacitance C
Osc. Output Capacitance C
Supply Current I

DD

DD

OUT

OUT

DISP

IN

OSC

OSC

OSC

BP

DB

OSC

OSCI

OSCO

DD

T

= +25°C 4.5 — — V

A

I

= 1.0 mA 5.5 — 6.8 V

DD

VDD = 5.0 V, V
V

= 5.0 V, V

DD

VDD = 5.0 V, V
VDD = 5.0 V, V

= 4.8 V -20 — — µA

OUT

= 0.2 V 120 — — µA

OUT

= 4.8 V -80 — — µA

OUT

= 0.2 V 240 — — µA

OUT

VDD ≥5.0 V 4.0 — — V
S1, S2, DATA, or SELECT -55 — -700 µA

— 4.194 304 — MHz
VDD = Zener voltage — — 200 ms
∆VDD = ±100 mV — — ±1.0 ppM

—64—Hz

0 — 62.5 ms
—16—MΩ
—15—pF
—30—pF

VDD = 5.0 V — — 1.0 mA

NOTE: Negative current is defined as coming out of (sourcing) the specified device terminal.

DISPLAY FORMAT

a1 a2 a3 a4

AM

PM

g1 g2 g3 g4

c1 c3c2 c4e1 e3e2 e4

d1 d2 d3 d4

f2 f4f3

b2 b4b1 b3

COLON

Dwg. No. OC-001

5616

2-FUNCTION, 4-DIGIT LCD AUTOMOTIVE CLOCK

FUNCTIONAL DESCRIPTION

DATA Logic Levels are VDD and Ground

Power-Up Reset. When power up occurs, the hours and minutes
counters are reset, and the clock starts running:

Operation

12-Hour mode and counting starts from 1:00 AM

Programming Modes. Data is loaded by pulling DATA low (1 µs pulse
duration) n times to set the desired bits for frequency correction into
the data input register. This information is latched in the RAM, thus
allowing the testing of the oscillator frequency adjustment without
storing the selected pattern in the PROM cells. The data latched in the
RAM is stored in the PROM cells when DATA is held low for a mini­mum of 10 ms.

The data stored in the data input register is cleared on any SELECT
transition (low to high or high to low). It is also cleared when the
program power voltage (VPP) is reduced from 18 V to VDD. Clearing the
data input register does not affect the data latched in the RAM.

Program DATA SELECT

V

PP

V

D

V

S

Operation

18 V Pulse Ground DATA load for frequency correction
18 V Ground V

V

DD

V

DD

Ground Verify stored data

DD

DATA store

FREQUENCY CORRECTION

FREQUENCY CORRECTION

V

PP

t

PHDL

V

D

V

S

VERIFY CYCLE (V = V )

V

S

123

t

DLH

t

SVDL

t

PP DD

SLDV

127 MAX

t

wD

t

PLSX

t

DHL

SEGMENT OUTPUTS

t

DHPL

t

SHDX

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

Dwg. No. WC-001-1

5616

2-FUNCTION, 4-DIGIT LCD AUTOMOTIVE CLOCK

Frequency Correction. The on-chip oscillator circuit increases the
crystal frequency approximately 40 ppm. This ensures that the typical
crystal will operate within the tuning range. With VS at ground, data
pulses are then used to trim the internal clock frequency by 2 to 254
ppm to the required value. The quantity of data pulses needed (1 to

127) is
n = f

128 x 10

where fBP is the measured frequency at BACKPLANE. Prior to trim­ming, it must be between 64.000 128 Hz and 64.016 256 Hz.

Operating Modes. The operating modes of the clock are controlled
by the voltages applied to VPP, SELECT, IGNITION, and switches S1
and S2.

Program SELECT
V

PP

V

DD

V

DD

18 V Ground Open Open X Programming

V

S

V

DD

V

DD

- 64

BP

-6

S1 S2 IGNITION Mode

Open Open X Clock running

Ground Ground 12 V Diagnostic

X = Irrelevant, ground or 12 V

Clock Running Mode. During the clock running mode, setting
functions are achieved by either momentary or continuous operation
of switches S1 and S2, which are enabled by IGNITION. Hours or
minutes are incremented on S1 or S2 (respectively) depression and
continue at a 1 Hz rate while the switch is depressed.

S1 S2 IGNITION Operation

Open Open X Clock running

X X Ground Setting disabled
Ground Open 12 V Set hours
Open Ground 12 V Set Minutes
Ground Ground 12 V Change counting sequence (12 to 24 hour

or 24 to 12 hour)

X = Irrelevant, ground or 12 V for IGNITION, ground or open for S1 and S2

Diagnostic Mode. To enter the diagnostic mode, S1 and S2 are oper­ated with IGNITION connected to 12 V. All segments are displayed for
as long as S1 and S2 are depressed. On opening S1 and S2, the clock
will leave the diagnostic mode and go through a power-up sequence.
In the SCL5616HW, the counting sequence will change (from 12 hour
to 24 hour or from 24 hour to 12 hour). To inhibit the power-up reset,
hold the DATA input low (ground). The counting mode will change
without resetting the hours or minutes counters.

5616

2-FUNCTION, 4-DIGIT LCD AUTOMOTIVE CLOCK

Stored Data Verification. In the verify mode, the complement value
of the information stored in the PROM cells is brought out directly to
the segment output terminals for easy verification of the stored data.
If a bit is programmed (high), the appropriate segment output is turned
ON (low). The segments represent the binary equivalent of the
number of frequency correction data pulses entered.

Frequency Selection Pulses 64 32 16 8421
Segment b4 c4 d4 e4 c3 e3 c2

RECOMMENDED FLASH

PROGRAMMING CHARACTERISTICS

at T

= +25°C, Logic Levels are V

A

Characteristic Symbol Min. Max. Units

(except PROGRAM High)

and Ground

DD

PROGRAM High (18 V) to DATA Low t
SELECT Valid to DATA Low t
DATA Low to DATA High t
DATA High to DATA Low
DATA Store Pulse Duration t
DATA High to PROGRAM Low t
PROGRAM Low to SELECT Change t
SELECT Low (Verify) to DATA Valid t
DATA Hold from End of Verify t

PHDL

SVDL

DLH

t

DHL

wD

DHPL

PLSX

SLDV

SHDX

1.0 — µs
25 — µs

1.0 1.5 µs

1.0 — µs
10 — ms

1.0 — µs

1.0 — µs
— 1.0 µs
—10ns

Allegro MicroSystems, Inc. reserves the right to
make, from time to time, such departures from the detail
specifications as may be required to permit improve­ments in the design of its products.

The information included herein is believed to be
accurate and reliable. However, Allegro MicroSystems,
Inc. assumes no responsibility for its use; nor for any
infringements of patents or other rights of third parties
which may result from its use.

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]