Document
74ALVC16839 Low Voltage 20-Bit Selectable Register/Buffer with 3.6V Tolerant Inputs and Outputs
December 2001 Revised December 2001
74ALVC16839 Low Voltage 20-Bit Selectable Register/Buffer with 3.6V Tolerant Inputs and Outputs
General Description
The ALVC16839 contains twenty non-inverting selectable buffered or registered paths. The device can be configured to operate in a registered, or flow through buffer mode by utilizing the register enable (REGE) and Clock (CLK) signals. The device operates in a 20-bit word wide mode. All outputs can be placed into 3-STATE through use of the OE pin. These devices are ideally suited for buffered or registered 168 pin and 200 pin SDRAM DIMM memory modules. The 74ALVC16839 is designed for low voltage (1.65V to 3.6V) VCC applications with I/O compatibility up to 3.6V. The 74ALVC16839 is fabricated with an advanced CMOS technology to achieve high speed operation while maintaining low CMOS power dissipation.
Features
s Compatible with PC100 and PC133 DIMM module specifications s 1.65V to 3.6V VCC supply operation s 3.6V tolerant inputs and outputs s tPD (CLK to O n) 3.7 ns max for 3.0V to 3.6V VCC 4.9 ns max for 2.3V to 2.7V VCC 8.8 ns max for 1.65V to 1.95V VCC s Power-off high impedance inputs and outputs s Supports live insertion and withdrawal (Note 1) s Uses patented noise/EMI reduction circuitry s Latchup conforms to JEDEC JED78 s ESD performance: Human body model > 2000V Machine model > 200V
Note 1: To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pull-up resistor; the minimum value of the resistor is determined by the current-sourcing capability of the driver.
Ordering Code:
Order Number 74ALVC16839MTD Package Number MTD56 Package Descriptions 56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Devices also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
Logic Symbol
Pin Descriptions
Pin Names OE I0–I19 O0–O19 CLK REGE Description Output Enable Input (Active LOW) Inputs Outputs Clock Input Register Enable Input
© 2001 Fairchild Semiconductor Corporation
DS500713
www.fairchildsemi.com
74ALVC16839
Connection Diagram
Truth Table
Inputs CLK REGE H H L L X In H L H L X OE L L L L H Outputs On H L H L Z
↑ ↑
X X X
H = Logic HIGH L = Logic LOW X = Don’t Care, but not floating Z = High Impedance ↑ = LOW-to-HIGH Clock Transition
Functional Description
The 74ALVC16839 consists of twenty selectable noninverting buffers or registers with word wide modes. Mode functionality is selected through operation of the CLK and REGE pin as shown by the truth table. When REGE is held at a logic HIGH the device operates as a 20-bit register. Data is transferred from In to On on the rising edge of the CLK input. When the REGE pin is held at a logic LOW the device operates in a flow through mode and data propagates directly from the In to the On outputs. All outputs can be 3-stated by holding the OE pin at a logic HIGH.
Logic Diagram
www.fairchildsemi.com
2
74ALVC16839
Absolute Maximum Ratings(Note 2)
Supply Voltage (VCC) DC Input Voltage (VI) Output Voltage (VO) (Note 3) DC Input Diode Current (IIK) VI < 0V DC Output Diode Current (IOK) VO < 0V DC Output Source/Sink Current (IOH/IOL) DC VCC or GND Current per Supply Pin (ICC or GND) Storage Temperature Range (TSTG)
−0.5V to +4.6V −0.5V to 4.6V −0.5V to VCC +0.5V −50 mA −50 mA ±50 mA ±100 mA −65°C to +150°C
Recommended Operating Conditions (Note 4)
Power Supply Operating Input Voltage (VI) Output Voltage (VO) Free Air Operating Temperature (TA) Minimum Input Edge Rate (∆t/∆V) VIN = 0.8V to 2.0V, VCC = 3.0V 10 ns/V
Note 2: The Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the Absolute Maximum Ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation. Note 3: IO Absolute Maximum Rating must be observed. Note 4: Floating or unused inputs must be held HIGH or LOW.
1.65V to 3.6V 0V to VCC 0V to VCC
−40°C to +85°C
DC Electrical Characteristics
Symbol VIH Parameter HIGH Level Input Voltage Conditions VCC (V) 1.65 -1.95 2.3 - 2.7 2.7 - 3.6 VIL LOW Level Input Voltage 1.65 -1.95 2.3 - 2.7 2.7 - 3.6 VOH HIGH Level Output Voltage IOH = −100 µA IOH = −4 mA IOH = −6 mA IOH = −12 mA 1.65 - 3.6 1.65 2.3 2.3 2.7 3.0 IOH = −24 mA VOL LOW Level Output Voltage IOL = 100 µA IOL = 4 mA IOL = 6 mA IOL = 12mA IOL = 24 mA II IOZ ICC ∆ICC Input Leakage Current 3-STATE Output Leakage Quiescent Supply Current Increase in ICC per Input 0 ≤ VI ≤ 3.6V 0 ≤ VO ≤ 3.6V VI = V CC or GND, IO = 0 VIH = VCC − 0.6V 3.0 1.65 - 3.6 1.65 2.3 2.3 2.7 3 3.6 3.6 3.6 3 -3.6 VCC - 0.2 1.2 2 1.7 2.2 2.4 2 0.2 0.45 0.4 0.7 0.4 0.55 ±5.0 ±10 40 750 µA µA µA µA V V Min 0.65 x VCC 1.7 2.0 0.35 x VCC 0.7 0.8.