8同相三态缓冲器驱动器。可用于增大驱动电流的情况，比如单片机输出驱动数码管电流不够，就可利用74HC244来驱动数码管，增加亮度。 The 74HC244; 74HCT244 is an 8-bit buffer/line driver with 3-state outputs. The device can be used as two 4-bit buffers or one 8-bit buffer. The device features two output enables (1OE and 2OE), each controlling four of the 3-state ou
NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state 5. Pinning information 5.1 Pinning 74Hc244 74Hc244 74HcT244 74HcT244 terminal 1 ndex area 1A0[2 1920E 2Y0|3 181Y0 92E 2Y03 2Y15 161Y1 1A1[4 (172A0 1A26 15|2A1 (161Y1 2Y2|7 141Y2 1A2|6) 132A2 (152A1 1A3 2Y3 2 2Y2[7 1Y2 GND 1A3[8)|GND()(132A2 0018a0011 2Y3[9 121￥3 2 Transparent top view (1)This is not a supply pin the substrate is attached to this pad using conductive die attach material. There is no electrical or mechanical requirement to solder this pad However, if it is soldered the solder land should remain floating or be connected to GNd Fig 4. Pin configuration DIP20, SO20, (T)SSOP20 Fig 5. Pin configuration DHVQFN20 5.2 Pin description Table 2. Pin description Symbol Pin Description 10E. 20E 1,19 output enable input(active LOW) 1A0,1A1,1A2,1A3 2,4,6,8 data input 2Y0,2Y1,2Y2,2Y3 3,5,7,9 bus output GND 10 ground(O v) 2A0.2A1.2A2.2A3 17.15.13.11 data input 1Y0,1Y1,1Y2,1Y3 18.16.14.12 bus output 20 upply voltag 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 3of18 NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state 6. Functional description Table 3. Function table[1] Input Dutput noE MAn nYn H [1 H=HIGH voltage level; L= LOW voltage level; X=dont care; 2= high-impedance OFF-state 7. Limiting values Table 4. Limiting values In accordance with the Absolute Maximum Rating System(EC 60134). Voltages are referenced to GNd (ground=0 VI Symbol Parameter Conditions Min Max Unit supply voltage 0.5+7 input clamping current V1<-05V or Vi> Vcc +0.5 V +20 mA output clamping current Vo <-0.5Vor Vo>vcc +0 output current -0.5V<Vo<Vcc+0.5V ±35 AAA supply current 70 ground current 70 T stg storage temperature +150 total power dissipation DIP20 package 「] 750 mw So20. SSOP20 TSSOP20 and [2]- 500 mW DHVQFN20 packages [1 For DIP20 package: Ptot derates linearly with 12 mW/K above 70 [2] For so20 packages: Ptot derates linearly with 8 mW/K above 70C For SSoP20 and TSSOP 20 packages: Ptot derates linearly with 5.5 mW/K above 60C For DHVQFN20 packages: above 60C. Ptot derates linearly with 4.5 mW/K 8. Recommended operating conditions Table 5. Recommended operating conditions Symbol Parameter Conditions Min Max Unit 74Hc244 supply voltage 2.0 50 6.0 nput voltage CC output voltage nput transition rise and fall rate Vcc =2.0 V 625 ns/v cC=4.5V 1.67 139 ns/v ICC=6.0V ambient temperature 40 +125 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 4of18 NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state Table 5. Recommended operating conditions . continued Symbol Parameter Conditions Min Typ Max Unit 74HcT244 supply voltage 4.5 5.5 put voltage output voltage △t/△V input transition rise and fall rate Vcc=4.5 V 1.67 139 amb ambient temperature 40 +125 C 9. Static characteristics Table 6. Static characteristics At recommended operating conditions; voltages are referenced to GND (ground=0 v) Symbol Parameter Conditions 25°C -40°cto+8540°to+125° Unit Min TypMaxMinMa ax Min Max 74Hc244 HIGH-level Vcc=2.0 V 1.51.2 1.5 put voltage Vcc=4.5V 3.1524 3.15 3.15 6.0V 4.23.2 4.2 4.2 LOW-level CC =2.0V 0.80 0.5 0.5V nput voltage∨cc=45V 2.11.35 1.35 1.35V 60V 2.81.8 18 1.8V HIGH-level V= VIh or VIL output voltage I=-20 HA; VCc=2.0 V 1.92.0 lo=-20μA;vcc=4.5V 4.5 lO =-20 HA; Vcc=6.0V 5960 59 5.9 lo=-60mA:Vcc=4.5V3.98432 3.8 lo=-7.8mA;Vcc=6.0V548581 5.34 5.2 LOW-level Vi= VIH or VI output voltage Io =20 HA; Vcc =2.0V 00.1 0.1 =20μA;Vcc=45∨ 00.1 0.1 0.1V lo= 20 HA; Vcc =6.0V 00.1 0.1 0.1 lo=6.0 mA; Vcc =4.5V 0.150.26 0.33 04V lo =7.8 mA; Vcc=6.0V 0.160.26 0.33 0.4V nput leakage Vi= Vcc or GND +0.1 10 1.01A current CC=6.0V OFF-state per input pin; V=VIH or VIL +0.5 +10 A output current Vo=Vcc or GND ther inputs at Vcc or GND Vcc =6.0V; o=0A supply current Vi= Vcc or GND: lo=0 A: 8.0 80 160 Vcc =6.0 V 35 pF capacitance 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 5of18 NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state Table 6. Static characteristics continued At recommended operating conditions: voltages are referenced to GNd ( ground=0 v Symbol Parameter Conditions 25°C 40°to+8540°to+125Unit Min Typ Max Mi Max Mir Ma ax 74HcT244 HIGH-level Vcc =4.5 V to 5.5 V 2.01.6 2.0 input voltage LOW-level Vcc =4.5 V to 5.5 V 1.20.8 08 0.8V nput voltage HIGH-level VI= VIh or VI; Vcc =4.5V output voltage |o=-20 HA 4.44.5 4.4 =-6mA 3.984.32 3.84 LOW-level V= VIH or VI; Vcc =4.5V output voltage lo=20μA 00.1 0.1 0.1V lo =6.0 mA 0.160.26 0.33 0.4V input leakage Vi=Vcc or GND: ±0.1 ±10A current IcC=5.5V loz OFF-state per input pin V= Vih or Vil --+0.5 ±10A output current Vo=Vcc or GND other inputs at Vcc or GND; Vcc =5.5V; o=0A supply current Vi= Vcc or GND 80 80 160 Vcc =5.5V; Io=0A additional per input pin 70252 343uA supply current Vi= Vcc-21V; other inputs at Vcc or GND Vcc=4.5V to 5.5 V IO =0A 35 capacitance 10. Dynamic characteristics Table 7. Dynamic characteristics GND=0V, for load circuit see Figure 8 Symbol Parameter Conditions 25°C _40cto+125°Unit Min TypMax Max C)(125C) 74Hc244 propagation delay nAn to nYn e Figure b VcC=2.0V 30 110 145 165ns 4.5V 22 33 ViC=5.0V; CL= 15 pF 9 Vcc=6.0V 19 24 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 6of18 NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state Table 7. Dynamic characteristics.. continued GND=0 V, for load circuit see Figure 8 Symbol Parameter Conditions 25°C 40°cto+125° C Unit Min Typ Max ax 85°c)(125c) enable tim noe to nYn, see Figure 7 Vcc=2.0V 36 150 225 Vcc=4.5V 13 30 45 Vcc=6.0V 10 26 38 disable time noE to nYn or see Figure 7 Vcc =2.0V 39 150 190 225 Vcc=4.5∨ 14 45 ns Vcc=6.0∨ ttransition time see Figure6 Vcc=2.0V 14 ns Vcc=4.5∨ 12 15 18 ns Vcc=6.0∨ 10 13 15 power dissipation per buffer; V=GND to Vcc 35 capacitance 74HcT244 propagation delay nAn to nYn see Figure 6 Vcc =4.5V Vcc=5.0V:Cl=15 pF ns enable time noE to nYn; Vcc =4.5 V; see [2- 15 30 38 45 ns Figure 7 disable time noe to nYn; Vcc=4.5V; see 15 Fiqure 7 transition time ′cc=45v; see Figure6 12 18 dissipation per buffer 35 F capacitance V=GND to Vcc-1.5 V [1]pd is the same as tpHL and tPLH [2 ten is the same as tpzh and tpzl [3 tdis is the same tt is the same as tthe and ttL CpD is used to determine the dynamic power dissipation(PD in uw) PD= CPD x Vcc2×fxN+∑ CL x Vcc2xfo) where: fi input frequency in MHz fo autput frequency in Mhz CL =output load capacitance in pF Vcc supply voltage in V, N= number of inputs switching 2(CL X Vcc2 x fo)=sum of outputs 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 7of18 NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state 11. Waveforms n input PLH 10% THL Measurement points are given in Table 8 Vol and voh are typical voltage output levels that occur with the output load Fig 6. Input(nAn)to output(nYn)propagation delays and output transition times noE input GND plZ tpzL nYn output LOW-to-OFF ′M OFF-to-LOW PHZ pzh nYn output HIGH-to-OFF V enabled disabled 001aae014 Measurement points are given in Table 8 Vol and voh are typical voltage output levels that occur with the output load Fig 7. 3-state enable and disable times Table 8. Measurement points Input Output 74HC244 0.5×Vcc 0.5×Vcc 0.1×Vcc 09×VCc 74HCT244 13V 1.3V 0.1×VcC 0.9×Vcc 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 8of18 NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state pulse 10% 0V一 positive 10% CC G DUT open Test data is given in Table Definitions test circuit RT =Termination resistance should be equal to output impedance Zo of the pulse generator CL =Load capacitance including jig and probe capacitance RL Load resistance S1=Test selection switch Fig 8. Test circuit for measuring switching times Table 9, Test data T Input Load S1 position C PHL, tPLH pzh, thZ PZL, PLZ 74Hc244 6ns 15 pF, 50 pF 1 ko2 open GND CC 74HCT244 3 V 15 pF, 50 pF 1 ko open GND 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 NXP Semiconductors 74Hc244:74HcT244 Octal buffer/line driver: 3-state 12. Package outline DIP20: plastic dual in-line package; 20 leads(300 mil) soT146-1 A2 z W(M) in 1 index 10 mm DIMENSIONS (inch dimensions are derived from the original mm dimensions) A A A UNIT max. min.max (1) max m4205132170.30362692640 1300.380232654622254762360825 0 0.254 3057.80 3 006800210.0141060025 0.140.320.39 inches0.170.020.1300510.0150.001.0450.2401030120310.30.010.078 Note 1. Plastic or metal protrusions of 0.25 mm(0.01 inch) maximum per side are not included OUTLINE REFERENCES EUROPEAN VERSION IEC JEDEC JEITA PROJECTION ISSUE DATE 399-1227 SoT146-1 MS001 SC603 03-02-13 Fig 9. Package outline SOT146-1(DIP20) 74HC HCT244 formation provided in this document is subject to legal disclaimers @NXP B V. 2012. All rights reserved Product data sheet Rev. 4-24 September 2012 10of18