© Semiconductor Components Industries, LLC, 2014
July, 2014 − Rev. 10
1 Publication Order Number:
MC14521B/D
MC14521B
24-Stage Frequency Divider
The MC14521B consists of a chain of 24 flip−flops with an input
circuit that allows three modes of operation. The input will function as a
crystal oscillator, an RC oscillator, or as an input buffer for an external
oscillator. Each flip−flop divides the frequency of the previous flip−flop
by two, consequently this part will count up to 2
24
= 16,777,216.
The count advances on the negative going edge of the clock.
The outputs of the last seven−stages are available for added flexibility.
Features
• All Stages are Resettable
• Reset Disables the RC Oscillator for Low Standby Power Drain
• RC and Crystal Oscillator Outputs Are Capable of Driving External
Loads
• Test Mode to Reduce Test Time
• V
DD
′ and V
SS
′ Pins Brought Out on Crystal Oscillator Inverter to
Allow the Connection of External Resistors for Low−Power Operation
• Supply Voltage Range = 3.0 Vdc to 18 Vdc
• Capable of Driving Two Low−Power TTL Loads or One Low−Power
Schottky TTL Load over the Rated Temperature Range
• NLV Prefix for Automotive and Other Applications Requiring
Unique Site and Control Change Requirements; AEC−Q100
Qualified and PPAP Capable
• This Device is Pb−Free and is RoHS Compliant
MAXIMUM RATINGS (Voltages Referenced to V
SS
)
Parameter
Symbol Value Unit
DC Supply Voltage Range V
DD
−0.5 to +18.0 V
Input or Output Voltage Range
(DC or Transient)
V
in
, V
out
−0.5 to V
DD
+0.5
V
Input or Output Current (DC or Transient)
per Pin
I
in
, I
out
±10 mA
Power Dissipation, per Package (Note 1) P
D
500 mW
Ambient Temperature Range T
A
−55 to +125 °C
Storage Temperature Range T
stg
−65 to +150 °C
Lead Temperature (8−Second Soldering) T
L
260 °C
Stresses exceeding those listed in the Maximum Ratings table may damage the
device. If any of these limits are exceeded, device functionality should not be
assumed, damage may occur and reliability may be affected.
1. Temperature Derating: “D/DW” Package: –7.0 mW/_C From 65_C To 125_C
This device contains protection circuitry to guard against damage due to high
static voltages or electric fields. However, precautions must be taken to avoid
applications of any voltage higher than maximum rated voltages to this
high−impedance circuit. For proper operation, V
in
and V
out
should be constrained
to the range V
SS
≤ (V
in
or V
out
) ≤ V
DD
.
Unused inputs must always be tied to an appropriate logic voltage level
(e.g., either V
SS
or V
DD
). Unused outputs must be left open.
http://onsemi.com
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
ORDERING INFORMATION
A = Assembly Location
WL, L = Wafer Lot
YY, Y = Year
WW, W = Work Week
G = Pb−Free Package
MARKING DIAGRAMS
SOIC−16
D SUFFIX
CASE 751B
1
16
14521BG
AWLYWW
1
PIN ASSIGNMENT
13
14
15
16
9
10
11
125
4
3
2
1
8
7
6
Q20
Q21
Q22
V
DD
IN 1
Q18
Q19
OUT 2
V
SS
4
RESET
Q24
V
SS
IN 2
V
DD
4
Q23
OUT1
