INTEGRATED CIRCUITS CBT6820 20-bit bus switch with precharged outputs and Schottky undershoot protection for live insertion Product specification 1999 Apr 05 Philips Semiconductors Product specification 20-bit bus switch with precharged outputs and Schottky undershoot protection for live insertion FEATURES CBT6820 PIN CONFIGURATION • TTL compatible inputs and outputs • 5Ω switch connection between two port A and port B • Thin shrink small outline (TSSOP) • Undershoot protection included to prevent shoot through level 48 1OE 1A1 2 47 2OE 1A2 3 46 1B1 1A3 4 45 1B2 1A4 5 44 1B3 1A5 6 43 1B4 BIASV 1 changes • Bias voltage pre-charges the outputs to minimize signal distortion during live insertion DESCRIPTION The CBT6820 provides twenty bits of high-speed TTL-compatible bus switching. The low on-state resistance of the switch allows bi-directional connections to be made while adding near-zero propagation delay. The device also precharges the B port to a user-selectable bias voltage (BIASV) to minimize live-insertion noise. The device is organized as two 10-bit switch with individual enable (OE) input. When OE is low, the switch is on and port A is connected to port B. When OE is high, the switch between port A and port B is open and the B port is precharged to BIASV through the equivalent of a 10-kΩ resistor. Special clamp circuitry and Schottky diode clamps to ground are used to prevent an under voltage on the A side (Vin < GND) from causing the B side precharge voltage to drop below the ‘‘1” state. 1A6 7 42 1B5 GND 8 41 GND 1A7 9 40 1B6 1A8 10 39 1B7 1A9 11 38 1B8 1A10 12 37 1B9 2A1 13 36 1B10 2A2 14 35 2B1 VCC 15 34 2B2 2A3 16 33 2B3 GND 17 32 GND 2A4 18 31 2B4 2A5 19 30 2B5 2A6 20 29 2B6 2A7 21 28 2B7 2A8 22 27 2B8 2A9 23 26 2B9 2A10 24 25 2B10 SA00520 QUICK REFERENCE DATA SYMBOL tPLH/tPHL CONDITIONS Tamb = 25°C; GND = 0V PARAMETER Propagation delay An to Bn or Bn to An CIN Input capacitance CI/O Input/output capacitance TYPICAL UNIT 0.25 ns 4.5 pF 9.5 pF CL = 50 pF, VCC = 5 V Outputs disabled; VO = 0 V or VCC ORDERING INFORMATION PACKAGES 48-Pin Plastic TSSOP Type II 1999 Apr 05 TEMPERATURE RANGE OUTSIDE NORTH AMERICA NORTH AMERICA DWG NUMBER –40°C to +85°C CBT6820 DGG CBT6820 DGG SOT362–1 2 853–2152 21177 Philips Semiconductors Product specification 20-bit bus switch with precharged outputs and Schottky undershoot protection for live insertion PIN DESCRIPTION CBT6820 LOGIC SYMBOL PIN NUMBER SYMBOL 1 BIASV 2, 3, 4, 5, 6, 7, 9, 10, 11,12 1A1–1A10 NAME AND FUNCTION Bias voltage 1 Port 1A1 to Port 1A10 8, 17, 32, 41 GND 13, 14, 16, 18, 19, 20, 21, 22, 23, 24 2A1–2A10 Port 2A1 to Port 2A10 15 VCC Positive supply voltage 35, 34, 33, 31, 30, 29, 28, 27, 26, 25 2B1–2B10 Port 2B1 to Port 2B10 46, 45, 44, 43, 42, 40, 39, 38, 37, 36 1B1–1B10 Port 1B1 to Port 1B10 48, 47 1OE, 2OE Switch enables BIASV Ground (V) 2, 13 46, 35 xA1 12, 24 36, 25 xA10 xB1 xB10 FUNCTION TABLE OE STATE L A Port = B Port H A Port = Z H B Port = BIASV 48, 47 xOE where x = 1 – 2 H = High voltage level L = Low voltage level Z = High impedance “off ” state SA00506 ABSOLUTE MAXIMUM RATINGS SYMBOL RATING UNIT –0.5 to +7.0 V –50 mA –0.5 to +7.0 V ±128 mA DC bias voltage –0.5 to +7.0 V Tstg Storage temperature range –65 to 150 °C øJA Plastic thin shrink small outline package (TSSOP) 104 °C/W VCC IIK VI ISW VBIASV PARAMETER CONDITIONS DC supply voltage DC clamp diode current DC input VI < 0 voltage1 DC continuous channel current VO = 0 to VCC NOTE: 1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed. RECOMMENDED OPERATING CONDITIONS LIMITS SYMBOL PARAMETER UNIT Min Max VCC DC supply voltage 4.0 5.5 V BIASV DC supply voltage 1.3 VCC V VIH High-level input voltage (control pin) 2.0 VIL Low-level Input voltage (control pin) Tamb Operating free-air temperature range 1999 Apr 05 –40 3 V 0.8 V +85 °C Philips Semiconductors Product specification 20-bit bus switch with precharged outputs and Schottky undershoot protection for live insertion CBT6820 DC ELECTRICAL CHARACTERISTICS LIMITS SYMBOL PARAMETER TEST CONDITIONS Tamb = –40°C to +85°C Min VIK Input clamp voltage VCC = 4.5V; II = –18mA µA VCC = 5.5V; IO = 0, VI = VCC or GND 2.5 mA Control pins2 VCC = 5.5V, one input at 3.4V, other inputs at VCC or GND 2.5 mA Input capacitance per OE pin VI= 3V or 0 4.5 pF Capacitance per port (OFF-state) VO = 3V or 0; switch off 9.5 pF VCC = 4.5V; BiasV = 2.4V; VO = 0, OE = VCC ICC Quiescent supply current ron3 VP IUSP On-resistance VCC = 4.5V; VI = 0V; II = 64mA 5 7 VCC = 4.5V; VI = 0V; II = 30mA 5 7 VCC = 4.5V; VI = 2.4V; II = –15mA 10 15 3.6 3.9 Pass voltage VIN = VCC = 4.5V; Iout = –100µA Undershoot static current protection4 VCC = 5.0V, VBias = VCC IB = –5µA, VB ≥ 3.0V 3.4 –10 NOTES: 1. All typical values are at VCC = 5V, TA = 25 C 2. This is the increase in supply current for each input that is at the specified TTL voltage level rather than VCC or GND 3. Measured by the voltage drop between the A and the B terminals at the indicated current through the switch. On–state resistance is determined by the lowest voltage of the two (A or B) terminals. 4. Force IUSP, measure VB ≥ 3V 1999 Apr 05 V mA VCC = 5.5V; VI = GND or 5.5V Output bias current (B pins) CI –1.2 ±5 Input leakage current (control pin) CO(OFF) UNIT Max –0.25 II IO ∆ICC Typ1 4 Ω V mA Philips Semiconductors Product specification 20-bit bus switch with precharged outputs and Schottky undershoot protection for live insertion CBT6820 AC CHARACTERISTICS FOR VCC = 5.0V ±0.5V RANGE GND = 0V; tr = tf ≤ 2.5ns; CL = 50pF. LIMITS SYMBOL PARAMETER WAVEFORM Tamb = –40 to +85°C TYP1 MIN Propagation delay; An to Bn; Bn to An2 1 tPZH 3-State output enable time OE to An; OE to Bn; BIASV = GND 2 1.3 tPZL 3-State output enable time OE to An; OE to Bn; BIASV = 3.0V 2 tPHZ 3-State output enable time OE to An; OE to Bn; BIASV = GND tPLZ 3-State output enable time OE to An; OE to Bn; BIASV = 3.0V tpd UNIT MAX 0.25 ns 3.1 5.3 ns 1.4 2.9 4.6 ns 2 1.7 2.8 4.5 ns 2 2.8 4.4 6.6 ns NOTE: 1. All typical values are measured at Tamb = 25°C and VCC = 5.0V 2. Warranted but not production tested. The propagation delay is based on the RC time constant of the typical ON-state resistance of the switch and a load capacitance of 50pF, when driven by an ideal voltage source (zero output impedance) AC WAVEFORMS TEST CIRCUIT AND WAVEFORMS VM = 1.5V, VIN = GND to 3.0V 7V 3V 1.5V 1.5V 500 Ω From Output Under Test Open GND INPUT 500 Ω CL = 50 pF 0V tPHL tPLH S1 Load Circuit VOH 1.5V 1.5V OUTPUT VOL SA00028 Waveform 1. Waveforms Showing the Input (An) to Output (Bn) Propagation Delays 1.5 V 3.5V Output Waveform 1 S1 at 7 V (see Note) 1.5 V Output Waveform 2 S1 at Open (see Note) VOL + 0.3V VOL tPHZ tPZH VOH VOH – 0.3V 1.5 V 0V Note: Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control. Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control. SA00029 Waveform 2. Waveforms Showing the 3-State Output Enable and Disable Times 1999 Apr 05 tPLZ/tPZL 7V tPHZ/tPZH open SA00012 0V tPLZ open NOTES: 1. All input pulses are supplied by generators having the following characteristics: PRR ≤ 10MHz, ZO = 50 Ω, tr ≤ 2.5 ns, tf ≤ 2.5 ns. 2. The outputs are measured one at a time with one transition per measurement. 1.5 V tPZL S1 tpd DEFINITIONS Load capacitance includes jig and probe capacitance; CL = see AC CHARACTERISTICS for value. 3V Output Control (Low-level enabling TEST 5 Philips Semiconductors Product specification 20–bit bus switch with precharged outputs and Schottky undershoot protection for live insertion TSSOP48: plastic thin shrink small outline package; 48 leads; body width 6.1mm 1999 Apr 05 6 CBT6820 SOT362-1 Philips Semiconductors Product specification 20–bit bus switch with precharged outputs and Schottky undershoot protection for live insertion NOTES 1999 Apr 05 7 CBT6820 Philips Semiconductors Product specification 20–bit bus switch with precharged outputs and Schottky undershoot protection for live insertion CBT6820 DEFINITIONS Data Sheet Identification Product Status Definition Objective Specification Formative or in Design This data sheet contains the design target or goal specifications for product development. Specifications may change in any manner without notice. Preliminary Specification Preproduction Product This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. Product Specification Full Production This data sheet contains Final Specifications. Philips Semiconductors reserves the right to make changes at any time without notice, in order to improve design and supply the best possible product. Philips Semiconductors and Philips Electronics North America Corporation reserve the right to make changes, without notice, in the products, including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified. Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. LIFE SUPPORT APPLICATIONS Philips Semiconductors and Philips Electronics North America Corporation Products are not designed for use in life support appliances, devices, or systems where malfunction of a Philips Semiconductors and Philips Electronics North America Corporation Product can reasonably be expected to result in a personal injury. Philips Semiconductors and Philips Electronics North America Corporation customers using or selling Philips Semiconductors and Philips Electronics North America Corporation Products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors and Philips Electronics North America Corporation for any damages resulting from such improper use or sale. Philips Semiconductors 811 East Arques Avenue P.O. Box 3409 Sunnyvale, California 94088–3409 Telephone 800-234-7381 Philips Semiconductors and Philips Electronics North America Corporation register eligible circuits under the Semiconductor Chip Protection Act. Copyright Philips Electronics North America Corporation 1998 All rights reserved. Printed in U.S.A.