IMX51A_10 Datasheet, PDF (29/172 Pages) Freescale Semiconductor, Inc – i.MX51A Automotive and Infotainment Applications Processors

Electrical Characteristics
4.4.2 DDR2 Output Buffer Impedance
Table 26 shows the DDR2 output buffer impedance.
Table 26. DDR2 I/O Output Buffer Impedance HVE = 0
Parameter Symbol
Test Conditions
Best Case
T_j = –40 °C
OVDD = 1.95 V
VCC = 1.3 V
Typical
T_j = 25 °C
OVDD = 1.8 V
VCC = 1.2 V
Worst Case
T_j = 105 °C
OVDD = 1.6 V
VCC = 1.1 V Unit
Output Driver
Impedance
Output Driver
Impedance
Rpu Low Drive Strength, Ztl = 150 Ω
Medium Drive Strength, Ztl = 75 Ω
High Drive Strength, Ztl = 50 Ω
Max Drive Strength
Rpd Low Drive Strength, Ztl = 150 Ω
Medium Drive Strength, Ztl = 75 Ω
High Drive Strength, Ztl = 50 Ω
Max Drive Strength
s0–s5
000000
185
92.5
61.7
26.5
190.3
95.1
63.4
27.6
s0–s5
101010
140
70
47
19.5
145.4
72.7
48.5
19.9
s0–s5
111111
111.4
Ω
55.7
37.2
15.4
120.6
Ω
60.3
40.2
16.9
4.4.3 UHVIO Output Buffer Impedance
Table 27 shows the UHVIO output buffer impedance.
Table 27. UHVIO Output Buffer Impedance
Parameter Symbol
Test Conditions
Output Driver
Impedance
Output Driver
Impedance
Rpu Low Drive Strength, Ztl = 150 Ω
Medium Drive Strength, Ztl = 75 Ω
High Drive Strength, Ztl = 50 Ω
Rpd Low Drive Strength, Ztl =1 50 Ω
Medium Drive Strength, Ztl = 75 Ω
High Drive Strength, Ztl = 50 Ω
Min
Typ
Max
OVDD OVDD OVDD OVDD OVDD OVDD ^Unit
1.95 V 3.0 V 1.875 V 3.3 V 1.65 V 3.6 V
98 114 124
49
57
62
32
38
41
135 198 206 Ω
67
99 103
45
66
69
97 118 126
49
59
63
32
40
42
154 179 217 Ω
77
89 109
51
60
72
NOTE
Output driver impedance is measured with long transmission line of
impedance Ztl attached to I/O pad and incident wave launched into
transmission lime. Rpu/Rpd and Ztl form a voltage divider that defines
specific voltage of incident wave relative to OVDD. Output driver
impedance is calculated from this voltage divider (see Figure 3).
i.MX51A Automotive and Infotainment Applications Processors, Rev. 2
Freescale Semiconductor
29
Preliminary—Subject to Change Without Notice