Rev.1.7 / Feb. 2013
3.3 Output Buffer Characteristics
3.3.1 Output AC Test Conditions
3.3.2 Output DC Current Drive
SSTL_18 Class II
Output Timing Measurement Reference Level
0.5 * VDDQ
1. The VDDQ of the device under test is referenced.
Output Minimum Source DC Current
1, 3, 4
Output Minimum Sink DC Current
2, 3, 4
1. VDDQ = 1.7 V; VOUT = 1420 mV. (VOUT - VDDQ)/IOH must be less than 21 ohm for values of VOUT between VDDQ
and VDDQ - 280 mV.
2. VDDQ = 1.7 V; VOUT = 280 mV. VOUT/IOL must be less than 21 ohm for values of VOUT between 0 V and 280
3. The dc value of VREF applied to the receiving device is set to VTT
4. The values of IOH(dc) and IOL(dc) are based on the conditions given in Notes 1 and 2. They are used to test
device drive current capability to ensure VIH min plus a noise margin and VIL max minus a noise margin are
delivered to an SSTL_18 receiver. The actual current values are derived by shifting the desired driver operating
point (see Section 3.3) along a 21 ohm load line to define a convenient driver current for measurement.