0
登录后你可以
  • 下载海量资料
  • 学习在线课程
  • 观看技术视频
  • 写文章/发帖/加入社区
会员中心
创作中心
发布
  • 发文章

  • 发资料

  • 发帖

  • 提问

  • 发视频

创作活动
SN75C3223DWG4

SN75C3223DWG4

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    SOIC20

  • 描述:

    IC TRANSCEIVER FULL 2/2 20SOIC

  • 数据手册
  • 价格&库存
SN75C3223DWG4 数据手册
                  SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 D D D D D D D D DB, DW, OR PW PACKAGE (TOP VIEW) Operate With 3-V to 5.5-V VCC Supply Operate Up To 1 Mbit/s Low Standby Current . . . 1 µA Typ External Capacitors . . . 4 × 0.1 µF Accept 5-V Logic Input With 3.3-V Supply Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II RS-232 Bus-Pin ESD Protection Exceeds ±15 kV Using Human-Body Model (HBM) Applications − Battery-Powered Systems, PDAs, Notebooks, Laptops, Palmtop PCs, and Hand-Held Equipment EN C1+ V+ C1− C2+ C2− V− DOUT2 RIN2 ROUT2 1 20 2 19 3 18 4 17 5 16 6 15 7 14 8 13 9 12 10 11 FORCEOFF VCC GND DOUT1 RIN1 ROUT1 FORCEON DIN1 DIN2 INVALID description/ordering information The SN65C3223 and SN75C3223 consist of two line drivers, two line receivers, and a dual charge-pump circuit with ±15-kV ESD protection pin to pin (serial-port connection pins, including GND). The devices provide the electrical interface between an asynchronous communication controller and the serial-port connector. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-V supply. The devices operate at data signaling rates up to 1 Mbit/s and a driver output slew rate of 24 V/µs to 150 V/µs Flexible control options for power management are available when the serial port is inactive. The auto-powerdown feature functions when FORCEON is low and FORCEOFF is high. During this mode of operation, if the device does not sense a valid RS-232 signal, the driver outputs are disabled. If FORCEOFF is set low and EN is high, both drivers and receivers are shut off, and the supply current is reduced to 1 µA. Disconnecting the serial port or turning off the peripheral drivers causes auto-powerdown to occur. Auto-powerdown can be disabled when FORCEON and FORCEOFF are high. With auto-powerdown enabled, the device is activated automatically when a valid signal is applied to any receiver input. The INVALID output is used to notify the user if an RS-232 signal is present at any receiver input. INVALID is high (valid data) if any receiver input voltage is greater than 2.7 V or less than −2.7 V or has been between −0.3 V and 0.3 V for less than 30 µs. INVALID is low (invalid data) if the receiver input voltage is between −0.3 V and 0.3 V for more than 30 µs. Refer to Figure 4 for receiver input levels. ORDERING INFORMATION SOIC − DW 0°C 0 C to 70 70°C C SSOP − DB TSSOP − PW SOIC − DW −40°C −40 C to 85 85°C C ORDERABLE PART NUMBER PACKAGE† TA SSOP − DB TSSOP − PW Tube of 25 SN75C3223DW Reel of 2000 SN75C3223DWR Reel of 2000 SN75C3223DBR Tube of 70 SN75C3223PW Reel of 2000 SN75C3223PWR Tube of 25 SN65C3223DW Reel of 2000 SN65C3223DWR Reel of 2000 SN65C3223DBR Tube of 70 SN65C3223PW Reel of 2000 SN65C3223PWR TOP-SIDE MARKING 75C3223 CA3223 CA3223 65C3223 CB3223 CB3223 † Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at www.ti.com/sc/package. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright  2004, Texas Instruments Incorporated       !"#$ % &'!!($ #%  )'*+&#$ ,#$( !,'&$% &!" $ %)(&&#$% )(! $-( $(!"%  (.#% %$!'"($% %$#,#!, /#!!#$0 !,'&$ )!&(%%1 ,(% $ (&(%%#!+0 &+',( $(%$1  #++ )#!#"($(!% POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1                  SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 Function Tables EACH DRIVER INPUTS DIN FORCEON OUTPUT FORCEOFF VALID RIN RS-232 LEVEL DRIVER STATUS DOUT X X L X Z Powered off L H H X H H H H X L Normal operation with auto-powerdown disabled L L H Yes H H L H Yes L L L H No Z H L H No Z Normal operation with auto-powerdown enabled Powered off by auto-powerdown feature H = high level, L = low level, X = irrelevant, Z = high impedance EACH RECEIVER INPUTS RIN EN VALID RIN RS-232 LEVEL OUTPUT ROUT L L X H H L X L X H X Z Open L No H H = high level, L = low level, X = irrelevant, Z = high impedance (off), Open = input disconnected or connected driver off logic diagram (positive logic) 17 13 DIN1 DOUT1 8 12 DIN2 FORCEOFF DOUT2 20 14 Auto-powerdown 11 INVALID FORCEON 1 EN 16 15 ROUT1 RIN1 9 10 ROUT2 2 RIN2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265                    SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage range, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 6 V Positive output supply voltage range, V+ (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 7 V Negative output supply voltage range, V− (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to −7 V Supply voltage difference, V+ − V− (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 V Input voltage range, VI: Driver, FORCEOFF, FORCEON, EN . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 6 V Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −25 V to 25 V Output voltage range, VO: Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −13.2 V to 13.2 V Receiver, INVALID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to VCC + 0.3 V Package thermal impedance, θJA (see Notes 2 and 3): DB package . . . . . . . . . . . . . . . . . . . . . . . . . . . 70°C/W DW package . . . . . . . . . . . . . . . . . . . . . . . . . . 58°C/W PW package . . . . . . . . . . . . . . . . . . . . . . . . . . 83°C/W Operating virtual junction temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTES: 1. All voltages are with respect to network GND. 2. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) − TA)/θJA. Operating at the absolute maximum TJ of 150°C can affect reliability. 3. The package thermal impedance is calculated in accordance with JESD 51-7. recommended operating conditions (see Note 4 and Figure 6) VCC = 3.3 V VCC = 5 V VCC = 3.3 V VCC Supply voltage VIH Driver and control high-level input voltage VIL Driver and control low-level input voltage VCC = 5 V DIN, EN, FORCEOFF, FORCEON Driver and control input voltage DIN, EN, FORCEOFF, FORCEON VI Receiver input voltage TA Operating free-air temperature DIN, EN, FORCEOFF, FORCEON MIN NOM MAX 3 3.3 3.6 4.5 5 5.5 UNIT V 2 V 2.4 0.8 0 5.5 −25 25 SN65C3223 −40 85 SN65C3223 0 70 V V °C NOTE 4: Test conditions are C1−C4 = 0.1 µF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 µF, C2−C4 = 0.33 µF at VCC = 5 V ± 0.5 V. electrical characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Note 4 and Figure 6) PARAMETER II ICC Input leakage current Supply current TEST CONDITIONS EN, FORCEOFF, FORCEON MIN TYP‡ MAX ±0.01 ±1 µA 0.3 1 mA Auto-powerdown disabled No load, FORCEOFF, FORCEON at VCC Powered off No load, FORCEOFF at GND 1 10 Auto-powerdown enabled No load, FORCEOFF at VCC, FORCEON at GND, All RIN are open or grounded 1 10 UNIT µA ‡ All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C. NOTE 4: Test conditions are C1−C4 = 0.1 µF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 µF, C2−C4 = 0.33 µF at VCC = 5 V ± 0.5 V. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3                   SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 DRIVER SECTION electrical characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Note 4 and Figure 6) PARAMETER TEST CONDITIONS MIN TYP† VOH VOL High-level output voltage DOUT at RL = 3 kΩ to GND 5 5.4 Low-level output voltage DOUT at RL = 3 kΩ to GND −5 −5.4 IIH IIL High-level input current VI = VCC VI at GND Low-level input current ±0.01 IOS Short-circuit output current‡ VCC = 3.6 V, VCC = 5.5 V, ro Output resistance VCC, V+, and V− = 0 V, VO = 0 V VO = 0 V VO = ±2 V VO = ±12 V, 300 MAX UNIT V V ±1 µA ±0.01 ±1 µA ±35 ±60 ±35 ±90 mA Ω 10M ±25 VCC = 3 V to 3.6 V µA VO = ±10 V, VCC = 4.5 V to 5.5 V ±25 † All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C. ‡ Short-circuit durations should be controlled to prevent exceeding the device absolute power-dissipation ratings, and not more than one output should be shorted at a time. NOTE 4: Test conditions are C1−C4 = 0.1 µF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 µF, C2−C4 = 0.33 µF at VCC = 5 V ± 0.5 V. Ioff Output leakage current FORCEOFF = GND switching characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Note 4 and Figure 6) PARAMETER Maximum data rate (see Figure 1) TEST CONDITIONS RL = 3 kΩ, kΩ One DOUT switching MIN CL = 1000 pF CL = 250 pF, TYP† CL = 1000 pF, VCC = 3 V to 4.5 V VCC = 4.5 V to 5.5 V See Figure 2 tsk(p) Pulse skew§ CL = 150 pF to 2500 pF, RL = 3 kΩ to 7 kΩ, SR(tr) Slew rate, transition region (see Figure 1) VCC = 3.3 V, RL = 3 kΩ to 7 kΩ CL = 150 pF to 1000 pF 1000 POST OFFICE BOX 655303 UNIT kbit/s 1000 300 18 † All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C. § Pulse skew is defined as |tPLH − tPHL| of each channel of the same device. NOTE 4: Test conditions are C1−C4 = 0.1 µF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 µF, C2−C4 = 0.33 µF at VCC = 5 V ± 0.5 V. 4 MAX 250 • DALLAS, TEXAS 75265 ns 150 V/µs                   SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 RECEIVER SECTION electrical characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Note 4 and Figure 6) PARAMETER VOH VOL MIN TYP† VCC − 0.6 VCC − 0.1 TEST CONDITIONS High-level output voltage IOH = −1 mA IOL = 1.6 mA Low-level output voltage VIT+ Positive-going input threshold voltage VCC = 3.3 V VCC = 5 V VIT− Negative-going input threshold voltage VCC = 3.3 V VCC = 5 V Vhys Ioff Input hysteresis (VIT+ − VIT−) MAX V 0.4 1.6 2.4 1.9 2.4 0.6 1.1 0.8 1.4 ±0.05 EN = VCC ri Input resistance VI = ±3 V to ±25 V 3 5 † All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C. NOTE 4: Test conditions are C1−C4 = 0.1 µF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 µF, C2−C4 = 0.33 µF at VCC = 5 V ± 0.5 V. V V V 0.5 Output leakage current UNIT V ±10 µA 7 kΩ switching characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Note 4) PARAMETER tPLH tPHL TEST CONDITIONS MIN TYP† MAX UNIT Propagation delay time, low- to high-level output CL= 150 pF, See Figure 3 150 ns Propagation delay time, high- to low-level output CL= 150 pF, See Figure 3 150 ns ten Output enable time CL= 150 pF, See Figure 4 RL = 3 kΩ, 200 ns tdis Output disable time CL= 150 pF, See Figure 4 RL = 3 kΩ, 200 ns tsk(p) Pulse skew‡ See Figure 3 50 † All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C. ‡ Pulse skew is defined as |tPLH − tPHL| of each channel of the same device. NOTE 4: Test conditions are C1−C4 = 0.1 µF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 µF, C2−C4 = 0.33 µF at VCC = 5 V ± 0.5 V. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 ns 5                   SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 AUTO-POWERDOWN SECTION electrical characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Figure 5) PARAMETER TEST CONDITIONS MIN VT+(valid) Receiver input threshold for INVALID high-level output voltage FORCEON = GND, FORCEOFF = VCC VT−(valid) Receiver input threshold for INVALID high-level output voltage FORCEON = GND, FORCEOFF = VCC −2.7 VT(invalid) Receiver input threshold for INVALID low-level output voltage FORCEON = GND, FORCEOFF = VCC −0.3 VOH INVALID high-level output voltage IOH = −1 mA, FORCEOFF = VCC FORCEON = GND, VOL INVALID low-level output voltage IOL = 1.6 mA, FORCEOFF = VCC FORCEON = GND, MAX UNIT 2.7 V V 0.3 V VCC − 0.6 V 0.4 V switching characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Figure 5) TYP† PARAMETER tvalid tinvalid UNIT Propagation delay time, low- to high-level output 1 µs Propagation delay time, high- to low-level output 30 µs 100 µs ten Supply enable time † All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C. PARAMETER MEASUREMENT INFORMATION 3V Input Generator (see Note B) 1.5 V RS-232 Output 50 Ω RL 1.5 V 0V CL (see Note A) tTHL 3V FORCEOFF Output tTLH 3V −3 V TEST CIRCUIT 3V −3 V VOH VOL VOLTAGE WAVEFORMS SR(tr) + t THL 6V or t TLH NOTES: A. CL includes probe and jig capacitance. B. The pulse generator has the following characteristics: PRR = 250 kbit/s, ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns. Figure 1. Driver Slew Rate 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265                   SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 PARAMETER MEASUREMENT INFORMATION 3V Generator (see Note B) Input RS-232 Output 50 Ω 0V tPHL CL (see Note A) RL 3V FORCEOFF 1.5 V 1.5 V tPLH VOH 50% 50% Output VOL TEST CIRCUIT VOLTAGE WAVEFORMS NOTES: A. CL includes probe and jig capacitance. B. The pulse generator has the following characteristics: PRR = 250 kbit/s, ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns. Figure 2. Driver Pulse Skew EN 0V 3V Input 1.5 V 1.5 V −3 V Output Generator (see Note B) 50 Ω tPHL CL (see Note A) tPLH VOH 50% Output 0V FORCEOFF 50% VOL TEST CIRCUIT VOLTAGE WAVEFORMS NOTES: A. CL includes probe and jig capacitance. B. The pulse generator has the following characteristics: ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns. Figure 3. Receiver Propagation Delay Times 3V FORCEON 3 V or 0 V VCC S1 GND 1.5 V −3 V tPHZ (S1 at GND) Output CL (see Note A) EN Generator (see Note B) 1.5 V tPHZ (S1 at GND) RL 3 V or 0 V Input VOH Output 50% 0.3 V tPLZ (S1 at VCC) 0.3 V 50 Ω Output 50% VOL tPZL (S1 at VCC) TEST CIRCUIT VOLTAGE WAVEFORMS NOTES: A. CL includes probe and jig capacitance. B. The pulse generator has the following characteristics: ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns. Figure 4. Receiver Enable and Disable Times POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7                   SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 PARAMETER MEASUREMENT INFORMATION 2.7 V 2.7 V 0V Receiver Input 0V 50 Ω tvalid 50% VCC 50% VCC 0V ten INVALID CL = 30 pF (see Note A) ≈V+ V+ 0.3 V VCC 0V 0.3 V Supply Voltages FORCEOFF FORCEON tinvalid DIN −3 V VCC INVALID Output Autopowerdown −2.7 V −2.7 V ROUT Generator (see Note B) 3V DOUT ≈V− V− TEST CIRCUIT VOLTAGE WAVEFORMS Valid RS-232 Level, INVALID High 2.7 V ÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎ Indeterminate 0.3 V 0V −0.3 V If Signal Remains Within This Region for More Than 30 µs, INVALID Is Low† Indeterminate −2.7 V Valid RS-232 Level, INVALID High † Auto-powerdown disables drivers and reduces supply current to 1 µA. NOTES: A. CL includes probe and jig capacitance. B. The pulse generator has the following characteristics: PRR = 5 kbit/s, ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns. Figure 5. INVALID Propagation Delay Times and Supply Enabling Time 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265                   SLLS538B − JUNE 2002 − REVISED OCTOBER 2004 APPLICATION INFORMATION 2 20 Autopowerdown 1 EN VCC C1+ FORCEOFF 19 + + C1 − 3 C3 † + V+ GND 18 − CBYPASS = 0.1 µF − 4 5 17 C1− 16 C2+ DOUT1 RIN1 + C2 − 6 15 C2− ROUT1 5 kΩ 7 C4 − 14 V− FORCEON + DOUT2 RIN2 ROUT2 8 13 9 12 10 11 DIN1 DIN2 INVALID 5 kΩ † C3 can be connected to VCC or GND. NOTE A: Resistor values shown are nominal. VCC vs CAPACITOR VALUES VCC C1 C2, C3, C4 3.3 V ± 0.3 V 5 V ± 0.5 V 3 V to 5.5 V 0.1 µF 0.047 µF 0.1 µF 0.1 µF 0.33 µF 0.47 µF Figure 6. Typical Operating Circuit and Capacitor Values POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 PACKAGE OPTION ADDENDUM www.ti.com 18-Aug-2022 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) Samples (4/5) (6) SN65C3223DBR ACTIVE SSOP DB 20 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 85 CB3223 Samples SN65C3223DW ACTIVE SOIC DW 20 25 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 85 65C3223 Samples SN65C3223PW ACTIVE TSSOP PW 20 70 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 85 CB3223 Samples SN65C3223PWR ACTIVE TSSOP PW 20 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 85 CB3223 Samples SN75C3223DBR ACTIVE SSOP DB 20 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 CA3223 Samples SN75C3223DWR ACTIVE SOIC DW 20 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 75C3223 Samples SN75C3223PW ACTIVE TSSOP PW 20 70 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 CA3223 Samples SN75C3223PWR ACTIVE TSSOP PW 20 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 CA3223 Samples (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
SN75C3223DWG4 价格&库存

很抱歉,暂时无法提供与“SN75C3223DWG4”相匹配的价格&库存,您可以联系我们找货

免费人工找货