DS38C86A CMOS BTL 9-Bit Latching Data Transceiver General Description The DS38C86A is a 9-bit BTL Latching Data Transceiver designed specifically for proprietary bus interfaces. The device is implemented in CMOS technology, and delivers all of the performance of its Bi-CMOS counterparts while consuming less then half of the power supply current of the DS3886A. The DS38C86A conforms to the IEEE 11941.1 (Backplane Transceiver Logic - BTL) Standard. The DS38C86A incorporates an edge-triggered latch in the driver path which can be bypassed during fall-through mode of operation and a transparent latch in the receiver path. The DS38C86A driver output configuration is an open drain which allows Wired-OR connection on the bus. A unique design reduces the bus loading to 3 pF typical. The driver also has high sink current capability to comply with the bus loading requirements defined within IEEE 11941.1 BTL specification. Backplane Transceiver Logic (BTL) is a signaling standard that was invented and first introduced by National Semiconductor, then developed by the IEEE to enhance the performance of backplane buses. BTL transceivers feature low output capacitance drivers to minimize bus loading, a 1V nominal signal swing for reduced power consumption and receivers with precision thresholds for maximum noise immunity. The BTL standard eliminates settling time delays that severely limit TTL bus performance, and thus provide significantly higher bus transfer rates. The backplane bus is intended to be operated with termination resistors (selected to match the bus impedance) connected to a 2.1V at both ends. The low voltage is typically 1V. The DS38C86A provides an alternative to high power Bipolar and BiCMOS devices with the use of CMOS technology. The CMOS technology enables the DS38C86A to operate at 50% of the ICC required by the Bi-CMOS DS3886A. This can have a major impact on system power consumption. For example, if a backplane is 128 bits wide, 16 devices (9 bits each) required per card. Also assume the backplane is one rack with 20 slots. Power dissipation savings for this application is calculated by the following equation: P = ICC-savings x Power supply voltage x number of devices P = 32 mA x 5.5V x 320 = 56 Watts The power dissipation savings may increase even more when; the system bus is wider than 128 bits, there are multiple racks in the system, or if the system includes a hot backup. This may double the power dissipation savings. Separate ground pins are provided for each BTL output minimize induced ground noise during simultaneous switching. The unique driver circuitry provides a maximum slew rate of 0.9V/ns which allows controlled rise and fall times to reduce noise coupling to adjacent lines. The receiver is a high speed comparator that utilizes a Bandgap reference for precision threshold control allowing maximum immunity to the BTL 1V signaling level. Separate QVCC and QGND pins are provided to minimize the effects of high current switching noise. The receiver output is TRI-STATE ® and fully TTL compatible. The DS38C86A supports live insertion as defined in IEEE 896.2 through the LI (Live Insertion) pin. To implement live insertion the LI pin should be connected to the live insertion power connector. If this function is not supported, the LI pin must be tied to the VCC pin. The DS38C86A also provides glitch free power up/down protection during power sequencing. The DS38C86A has two types of power connections in addition to the LI pin. They are the Logic VCC (VCC) and the Quiet VCC (QVCC). There are two Logic VCC pins on the DS38C86A that provide the supply voltage for the logic and control circuitry. Multiple connections are provided to reduce the effects of package inductance and thereby minimize switching noise. A voltage delta between VCC and QVCC should never exceed ± 0.5V because of ESD circuitry. When CD (Chip Disable) is high, An is in high impedance state and Bn is high. To transmit data (An to Bn), the T/R signal is high. When RBYP is high, the positive edge triggered flip-flop is in the transparent mode. When RBYP is low, the positive edge of the ACLK signal clocks the data. In addition, the ESD circuitry between the VCC pins and all other pins except for BTL I/O’s and LI pins requires that any voltage on these pins should not exceed the voltage on VCC +0.5V. There are three different types of ground pins on the DS38C86A; the logic ground (GND), BTL grounds (B0GND–B8GND) and the Bandgap reference ground (QGND). All of these ground reference pins are isolated within the chip to minimize the effects of high current switching transients. For optimum performance the QGND should be returned to the connector through a quiet channel that does not carry transient switching current. The GND and B0GND–B8GND should be connected to the nearest backplane ground pin with the shortest possible path. Since many different grounding schemes could be implemented and ESD circuitry exists on the DS38C86A, it is important to note that any voltage between ground pins, QGND, GND or B0GND–B8GND should not exceed ± 0.5V including power up/down sequencing. The DS38C86A is offered in a 48-pin 7 x 7 space saving PQFP package. The transceiver’s high impedance control and driver inputs are fully TTL compatible. TRI-STATE ® is a registered trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS012623 www.national.com DS38C86A CMOS BTL 9-Bit Latching Data Transceiver July 1998 n 1V Signal swings with 80 mA sink capability n Open drain bus-port outputs allow Wired-OR connection n Controlled rise and fall time to reduce noise coupling to adjacent lines n TTL compatible Driver and Control inputs n Built in Bandgap reference with separate QVCC and QGND pins for precise receiver thresholds n Individual bus-port ground pins n Tight skew — — Driver 2.0 ns max — Receiver 2.5 ns max Features n > 50% Less ICC then Bi-CMOS DS3886A n 9-Bit inverting BTL latching transceiver n Meets IEEE 1194.1 Standard on Backplane Transceiver Logic (BTL) n Very low bus-port capacitance — 3 pF typical n Supports live insertion n Glitch free power-up/down protection n Fast propagation delays — An to Bn (Fall-Thru Mode) 6.0 ns max — Bn to An (Bypass Mode) 7.0 ns max Connection Diagram DS012623-3 Ordering Information www.national.com NSID Package NS Package Number DS38C86AVB PQFP (7x7) VBH48A 2 Absolute Maximum Ratings (Notes 1, 2) Power Dissipation at 25˚C If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. PQFP (7x7) (VF48B) (VCC, QVCC, LI) +6.5V 260˚C Recommended Operating Conditions Driver Input and Receiver Output (An) −65˚C to +150˚C Lead Temperature (Soldering, 4 sec.) −0.5V to VCC + 0.5V −0.5V to VCC + 0.5V Receiver Input Current 12.5 mW/˚C Storage Temperature Range Supply Voltage Control Input Voltage 1.56W Derate PQFP Package ± 15 mA Bus Voltage (Bn) +6.5V Supply Voltage (VCC) Bus Termination Voltage +2.4V Bus Termination Voltage ESD Bn Pins (HBM) ≥2 kV Operating Free Air ESD other Pins (HBM) Temperature Min Typ Max Units +4.5 +5.0 +5.5 V +2.06 +2.1 +2.14 V 0 +25 +70 ˚C ≥1.5 kV (Note 12) DC Electrical Characteristics (Notes 2, 3) TA = 0˚C to +70˚C unless otherwise noted, VCC = 5V ± 10% Symbol Parameter Conditions Min Typ Max Units DRIVER AND CONTROL INPUTS (CD, T/R, An, ACLK, LE and RBYP) VIH Minimum Input High Voltage VIL Maximum Input Low Voltage 2.0 V IIH Input High Current VIN = VCC IIL Input Low Current VIN = 0V, (except An) −10 µA IIL Input Low Current VIN = 0V, (An) −100 µA VCL Input Diode Clamp Voltage ICLAMP = −12 mA −1.2 V 1.1 V 0.8 V 40 µA DRIVER OUTPUT/RECEIVER INPUT (Bn) VOLB Output Low Bus Voltage (Note 5) An = T/R = VCC, CD = 0V, IOL = 80 mA IOFF Output Low Bus Current An = CD = 0V, T/R = VCC, Bn = 0.75V −200 µA Output High Bus Current An = CD = 0V, T/R = VCC, Bn = 2.1V 300 µA IOLBZ Output Low Bus Current T/R = CD = VCC, Bn = 0.75V (Chip Disabled) −100 µA IOHBZ Output High Bus Current T/R = CD = VCC, Bn = 2.1V (Chip Disabled) 100 µA 0.75 0.9 VTH Receiver Input Threshold T/R = CD = 0V 1.47 1.55 1.62 V VCLP Positive Clamp Voltage VCC = Max or 0V, IBn = 1 mA 2.4 3.8 4.5 V VCLN Negative Clamp Voltage ICLAMP = −12 mA −1.2 V RECEIVER OUTPUT (An) VOH VOL IOZ Voltage Output High Voltage Output Low TRI-STATE Leakage Current Bn = 1.1V, IOH = −2 mA, T/R = CD = 0V 2.5 Bn = 1.1V, IOH = −100 µA, T/R = CD = 0V 4.0 4.8 V V Bn = 2.1V, T/R = CD = 0V, IOL = 24 mA 0.2 0.5 V Bn = 2.1V T/R = CD = 0V, IOL = 8 mA 0.1 0.3 V VIN = VCC, CD = VCC, T/R = 0V, Bn = 0.75V 10 µA VIN = 0.0V, CD = VCC, T/R = 0V, Bn = 0.75V −10 µA 3 www.national.com DC Electrical Characteristics (Notes 2, 3) (Continued) TA = 0˚C to +70˚C unless otherwise noted, VCC = 5V ± 10% Symbol Parameter Conditions Min Typ Max Units −120 µA RECEIVER OUTPUT (An) IOS Output Short Circuit Current Bn = 1.1V, T/R = CD = 0V (Note 4) −40 SUPPLY CURRENT ICC_DIS Standby Current (No Load) T/R = All An = VCC, CD = VCC, ACLK = LE = RBYP = VCC 15 22 mA ICCT Sum of QVCC, VCC, LI All Bn = 2.1, T/R = CD = LE = 0.5V, ACLK = RBYP = 3.4 24 31 mA ILI Live Insertion Current T/R = An = CD = RBYP = ACLK = 0.0V 1 3 mA T/R = All An = RBYP = VCC, CD = ACLK = 0V 1 3 mA AC Electrical Characteristics (Note 6) TA = 0˚C to +70˚C, VCC = 5V ± 10% DRIVER (REN = 0V for all conditions) Symbol Parameter Conditions Min Typ Max Units ns DRIVER TIMING REQUIREMENTS tPHL An to Bn, Prop Delay CD = 0V, T/R = RBYP = 3V 2.0 4.3 6.0 tPLH Fall-Thru Mode (Figures 1, 2) 2.0 3.8 6.0 ns tPHL ACLK to Bn, Prop. Delay CD = RBYP = 0V, T/R = 3V 2.0 4.5 6.0 ns tPLH Transparent Latch Mode (Figures 1, 4) 2.0 4.0 6.0 ns tPHL CD to Bn 3 5.3 7.5 ns tPLH tPHL T/R to Bn Enable Time CD = RBYP = 0V, T/R = 3V Disable Time (Figures 1, 3) 2.5 4.3 7.5 ns Enable Time CD = 0V, RBYP = 3V 9.0 16.0 22.0 ns Disable Time (Figures 10, 11) 2.0 6.6 8.0 ns Transition Time-Rise/Fall for Bn (20% to 80%) CD = RBYP = 0V, T/R = 3V 0.8 1.4 3.0 ns (Figures 1, 3)(Note 10) 1.0 SR Slew Rate is Calculated from 1.3V to 1.8V for Bn CD = RBYP = 0V, T/R = 3V tSKEW ACLK to Bn, Same Package Output to Output An to Bn, Same Package Output to Output tPLH tr tf 1.7 3.0 ns 0.5 0.9 V/ns (Note 7) 0.9 2.5 ns (Note 7) 0.9 2.0 ns (Figures 1, 2)(Note 10) DRIVER TIMING REQUIREMENTS (Figure 4) tS An to ACLK (Set-Up Time) 3.0 ns tH ACLK to An (Hold Time) 1.0 ns tPW ACLK Pulse Width 3.0 ns CD = RBYP = 0V, T/R = 3V RECEIVER tPHL Bn to An, Prop Delay CD = T/R = 0V, LE = 3V 3.0 4.8 7.0 tPLH Bypass Mode (Figures 5, 6) 3.0 5.0 7.0 ns tPHL LE to An, Prop Delay CD = T/R = 0V 4.0 5.7 7.5 ns tPLH Latch Mode tPLZ CD to An ns (Figures 5, 7) 4.0 5.7 7.5 ns Disable Time LE = VCC, Bn = 2.1V, T/R = 0V 3.0 6.3 10.0 ns tPZL Enable Time (Figures 8, 9) 2.5 3.5 10.0 ns tPHZ Disable Time LE = VCC, Bn = 1.1V, T/R = 0V 4.0 7.3 10.0 ns tPZH Enable Time (Figures 8, 9) 3.5 5.5 8.5 ns www.national.com 4 AC Electrical Characteristics (Note 6) (Continued) TA = 0˚C to +70˚C, VCC = 5V ± 10% DRIVER (REN = 0V for all conditions) Symbol Parameter Conditions Min Typ Max Units RECEIVER tPLZ Disable Time LE = VCC, Bn = 2.1V, CD = 0V 3.0 6.0 9.0 ns tPZL T/R to An Enable Time (Figures 10, 11) 3.0 5.0 9.0 ns tPHZ Disable Time LE = VCC, Bn = 1.1 CD = 0V 3.0 7.3 12.0 ns tPZH Enable Time (Figures 8, 9) 3.0 5.5 12.0 ns tSKEW LE to An, Same Package (Note 7) 0.6 2.5 ns Bn to An, Same Package (Note 7) 0.7 2.5 ns RECEIVER TIMING REQUIREMENTS (Figure 7) tS Bn to LE (Set-Up Time) 3 ns tH LE to Bn (Hold Time) 1 ns tPW LE Pulse Width 5 ns CD = 0V, T/R = 0V PARAMETERS NOT TESTED COUTPUT Capacitance at Bn (Note 9) 3 pF tNR Noise Rejection (Note 10) 1 ns Note 1: “Absolute Maximum Ratings” are these beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the device should be operated at these limits. The table of “Electrical Characteristics” provides conditions for actual device operation. Note 2: All input and/or output pins shall not exceed VCC+0.5V and shall not exceed the absolute maximum rating at any time, including power-up and power-down. This prevents the ESD structure from being damaged due to excessive currents flowing from the input and/or output pins to QVCC and VCC. There is a diode between each input and/or output to VCC which is forward biased when incorrent sequencing is applied. LI and Bn pins do not have power sequencing requirements with respect to VCC and QVCC. Furthermore, the difference between VCC and QVCC should never be greater than 0.5V at any time including power-up. Note 3: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. All typical values are specified under these conditions: VCC = 5V and TA = 25˚C, unless otherwise stated. Note 4: Only one output should be shorted at a time, and duration of the short should not exceed one second. Note 5: Referenced to appropriate signal ground. Do not exceed maximum power dissipation of package. Note 6: Input waveforms shall have a rise and fall time of 3 ns. Note 7: tSKEW is the absolute value defined as the difference seen in propagation delay between drivers (receivers) in the same package with identical load conditions. Note 8: This parameter is tested using TDR techniques described in 1194.0 BTL Backplane Design Guide. Note 9: This parameter is tested during device characterization. The measurements revealed that the part will reject 1 ns pulse width. Note 10: Futurebus+ transceivers are required to limit bus signal rise and fall times to no faster then 0.5 V/ns, measured between 1.3V to 1.8V (approximately 20% to 80% of the nominal voltage swing). The rise and fall times are measured with a transceiver loading equivalent to 12.5Ω ties to +2.1 VDC. Note 11: Capacitance includes jig and probe capacitance. Note 12: All pins meet 2 kV typical, one device failure observed between An and QVCC in ESD rel sample. Pin Description Pin Name No. of Pins Input/Output A0–A8 9 I/O ACLK 1 I Description TTL driver input and TRI-STATE receiver output Clock input for latch mode B0–B8 9 I/O BTL receiver input and driver output B0 GND–B8 GND 9 NA Driver output ground reduces ground bounce due to high current switching of driver outputs. (Note 11) CD 1 I GND 2 NA Chip disable LE 1 I LI 1 NA Power supply for live insertion. Boards that require live insertion should connect LI to the live insertion pin on the connector. (Note 12) Ground reference for switching circuits (Note 11) Latch enable NC 9 NA No connect QGND 1 NA Ground reference for receiver input bandgap reference and non-switching circuits (Note 12) QVCC 1 NA Power supply for bandgap reference and non-switching circuits (Note 12) RBYP 1 I Register bypass enable 5 www.national.com Pin Description (Continued) Pin Name No. of Pins Input/Output T/R 1 I VCC 2 NA Description Transmit/Receive (bar) — transmit (An to Bn), receive (Bn to An) Power supply for switching circuits (Note 12) CD T/R LE RBYP ACLK An Bn H X X X X Z H L H X H X L H L H X H X H L L H X L X X Bn0 L H X L ↑ H L L H X L ↑ L H L L H X X H L L L H X X L H L L L X X An0 X X = High or Low Logic state. Z = High impedance state. L = Low state. H = High state. ↑ = Low to High transition. An0 = No change from previous state. Bn0 = Np change from previous state. BTL = High and Low state are nominally 2.1V and 1.2V, respectively. CMOS = High and Low state are nominally VCC and 0V, respectively. www.national.com 6 Logic Diagram DS012623-15 7 www.national.com Test Circuits and Timing Waveforms (Note 11) DS012623-9 FIGURE 6. Receiver: Bn to An DS012623-4 FIGURE 1. Driver Propagation Delay Set-Up DS012623-5 FIGURE 2. Driver: An to Bn, CD to An DS012623-10 FIGURE 7. Receiver: Enable/Disable Set-Up DS012623-6 FIGURE 3. Driver: CD to Bn DS012623-11 FIGURE 8. Receiver: Enable/Disable Set-Up DS012623-7 FIGURE 4. Driver: ACLK to Bn, tS, tH, tPW DS012623-12 FIGURE 9. Receiver: CD to An, T/R to An (tPHZ and tPZH only) DS012623-8 FIGURE 5. Receiver: Propagation Delay Set-Up DS012623-13 FIGURE 10. T/R to An, T/R to Bn www.national.com 8 Test Circuits and Timing Waveforms (Note 11) (Continued) DS012623-14 FIGURE 11. T/R to Bn (tPHL and tPLH only) T/R to An (tPZL and tPLZ only) 9 www.national.com DS38C86A CMOS BTL 9-Bit Latching Data Transceiver Physical Dimensions inches (millimeters) unless otherwise noted 48-Lead (7mm x 7mm) Molded PQFP, JEDEC Order Number DS38C86AVB NS Package Number VBH48A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: [email protected] National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.