PRELIMINARY
CM3132
Application Information (cont’d)
1 PSOP-8 IC drives 1-DIMM single channel DDR-I and CPU Core VCORE rail
VCC
VCC
VDDQ
VDDQ=2.5V, 1A MAX,
1A CONTINUOUS
REGULATOR
VREF
CDDQ
EN_DDR
Enable DDR
Memory
DDR-I
MEMORY
VTT
REGULATOR
R
R
VREF=1.25V, 0.5A MAX,
0.1A CONTINUOUS
CM3132-02
PSOP-8
CTT
VCORE
REGULATOR
VCORE=1.5V, 1A MAX,
1A CONTINUOUS
VREF
CPU
CORE
+ I/O
CCORE
EN_CORE
Enable CORE
SENSE_CORE
GND
With 3.3VCC @ 1A (VDDQ), 0.1A (VTT), 1A (VCORE),
PD = (3.3-2.5) * 1.05 + (2.5-1.25) * 0.1 + (3.3-1.5) * 1 = 0.84 + 0.125 + 1.8 = 2.765W
With 3.0VCC @ 1A (VDDQ), 0.1A (VTT), 1A (VCORE),
PD = (3.0-2.5) * 1.05 + (2.5-1.25) * 0.1 + (3.0-1.5) * 1 = 0.525 + 0.125 + 1.5 = 2.15W
With 2.8VCC @ 1A (VDDQ), 0.1A (VTT), 1A (VCORE),
PD = (2.8-2.5) * 1.05 + (2.5-1.25) * 0.1 + (2.8-1.5) * 1 = 0.315 + 0.125 + 1.3 = 1.74W
Figure 6. Power Dissipation Calculations
PD = (Vcc-2.5)*Iddq + (2.5-1.25)*0.1 + (Vcc-Vcore)*Icore
PD - (Vcc-2.5)*Iddq - 0.125 = (Vcc-Vcore)*Icore
Icore = [PD - (Vcc-2.5)*Iddq - 0.125] / (Vcc-Vcore)
TJUNC = TAMB + PD * (θJA
)
P
D = (TAMB - TJUNC ) / (θJA
)
Derating (degC/W) 40 40 40 40 40 40 40 40 40
Ambient (degC)
85 85 85 60 60 60 40 40 40
Max Power (W)
Vcc (V)
1.6 1.6 1.6 2.3 2.3 2.3 2.8 2.8 2.8
3.3 3.0 2.8 3.3 3.0 2.8 3.3 3.0 2.8
1.5 1.5 1.5 1.5 1.4 1.0 1.5 1.2 1.1
1.0 0.8 0.5 1.0 1.0 1.0 1.0 1.0 1.0
0.4 0.7 1.0 0.7 1.0 1.0 1.0 1.0 1.4
JA= 40 oC/W
θ
Min Vcore (V)
Max Iddq (A)
Max Icore (A)
Derating (degC/W) 60 60 60 60 60 60 60 60 60
Ambient (degC)
85 85 85 60 60 60 40 40 40
Max Power (W)
Vcc (V)
1.1 1.1 1.1 1.5 1.5 1.5 1.8 1.8 1.8
3.3 3.0 2.8 3.3 3.0 2.8 3.3 3.0 2.8
1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.4
0.3 0.5 0.6 1.0 0.7 0.5 0.5 0.7 1.0
0.4 0.5 0.6 0.3 0.7 0.9 0.7 1.0 1.0
JA= 60 oC/W
θ
θ
Min Vcore (V)
Max Iddq (A)
Max Icore (A)
Derating (degC/W) 80 80 80 80 80 80 80 80 80
Ambient (degC)
85 85 85 60 60 60 40 40 40
Max Power (W)
Vcc (V)
0.8 0.8 0.8 1.1 1.1 1.1 1.4 1.4 1.4
3.3 3.0 2.8 3.3 3.0 2.8 3.3 3.0 2.8
1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5
0.3 0.3 0.3 0.5 0.5 0.5 0.5 0.7 0.5
0.2 0.4 0.5 0.3 0.5 0.7 0.5 0.6 0.8
JA= 80 oC/W
Min Vcore (V)
Max Iddq (A)
Max Icore (A)
Figure 7. Power Derating Table
© 2004 California Micro Devices Corp. All rights reserved.
10 430 N. McCarthy Blvd., Milpitas, CA 95035-5112
●
Tel: 408.263.3214
●
Fax: 408.263.7846
●
www.calmicro.com
10/13/04
CALMIRCO [ CALIFORNIA MICRO DEVICES CORP ]
