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74HC191DB

Presettable synchronous 4-bit binary up/down counter

The 74HC191 is an asynchronously presettable 4-bit binary up/down counter. It contains four master/slave flip-flops with internal gating and steering logic to provide asynchronous preset and synchronous count-up and count-down operation. Asynchronous parallel load capability permits the counter to be preset to any desired value. Information present on the parallel data inputs (D0 to D3) is loaded into the counter and appears on the outputs when the parallel load (PL) input is LOW. This operation overrides the counting function. Counting is inhibited by a HIGH level on the count enable (CE) input. When CE is LOW internal state changes are initiated synchronously by the LOW-to-HIGH transition of the clock input. The up/down (U/D) input signal determines the direction of counting as indicated in the function table. The CE input may go LOW when the clock is in either state, however, the LOW-to-HIGH CE transition must occur only when the clock is HIGH. Also, the U/D input should be changed only when either CE or CP is HIGH. Overflow/underflow indications are provided by two types of outputs, the terminal count (TC) and ripple clock (RC). The TC output is normally LOW and goes HIGH when a circuit reaches zero in the count-down mode or reaches '15' in the count-up-mode. The TC output will remain HIGH until a state change occurs, either by counting or presetting, or until U/D is changed. ....

Not recommended for new designs (NRND).

Orderable parts

Type number Orderable part number Ordering code (12NC) Package Buy from distributors
74HC191DB 74HC191DB,118 935188600118 SOT338-1 Order product
74HC191DB 74HC191DB,112 935188600112 SOT338-1 Order product

Features and benefits

  • Complies with JEDEC standard no. 7A
  • CMOS input levels
  • Synchronous reversible counting
  • Asynchronous parallel load
  • Count enable control for synchronous expansion
  • Single up/down control input
  • ESD protection:
    • HBM JESD22-A114F exceeds 2000 V
    • MM JESD22-A115-A exceeds 200 V
  • Specified from -40 °C to +85 °C and -40 °C to +125 °C

Applications

Parametrics

Type numberProduct statusVCC (V)Output drive capability (mA)Logic switching levelstpd (ns)Power dissipation considerationsTamb (°C)Rth(j-a) (K/W)Ψth(j-top) (K/W)Package name
74HC191DB
NRND
Not for design in2.0 - 6.0+/- 5.2CMOS22low-40~12514842.0SSOP16

Package

Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackagePackage informationReflow-/Wave solderingPacking
74HC191DB
NRND
74HC191DB,118
( 9351 886 00118 )
ActiveHC191
SSOP16
(SOT338-1)
SOT338-1SSOP-TSSOP-VSO-REFLOW
SSOP-TSSOP-VSO-WAVE
Reel 13" Q1/T1
74HC191DB,112
( 9351 886 00112 )
ActiveHC191Bulk Pack

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFMSLMSL leadfree
74HC191DB
NRND
74HC191DB,11874HC191DB11
74HC191DB
NRND
74HC191DB,11274HC191DB11
Quality and reliability disclaimer

Documentation (5)

File nameTitleTypeDate
74HC191Presettable synchronous 4-bit binary up/down counterData sheet2019-08-13
AN11044Pin FMEA 74HC/74HCT familyApplication note2019-01-09
HCT_USER_GUIDEHC/T User GuideUser manual1997-10-31
SSOP-TSSOP-VSO-WAVEFootprint for wave solderingWave soldering2009-10-08
SSOP-TSSOP-VSO-REFLOWFootprint for reflow solderingReflow soldering2009-10-08

Support

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Ordering, pricing & availability

Type numberOrderable part numberOrdering code (12NC)PackingBuy online
74HC191DB74HC191DB,118935188600118Reel 13" Q1/T1Order product
74HC191DB74HC191DB,112935188600112Bulk PackOrder product

Sample

As a Nexperia customer you can order samples via our sales organization or directly via our Online Sample Store: https://extranet.nexperia.com.

Sample orders normally take 2-4 days for delivery.

If you do not have a direct account with Nexperia our network of global and regional distributors is available and equipped to support you with Nexperia samples.