MPC862/857T/857DSL PowerQUICC™ Family Hardware Specifications, Rev. 3
12 Freescale Semiconductor
Thermal Calculation and Measurement
7 Thermal Calculation and Measurement
For the following discussions, PD= (VDD x IDD) + PI/O, where PI/O is the power dissipation of the I/O
drivers.
7.1 Estimation with Junction-to-Ambient Thermal Resistance
An estimation of the chip junction t emperat ure, TJ, in °C can be obtained from the equation:
TJ = TA +(RθJA x PD)
where:
TA = ambient temperature (ºC)
RθJA = package junction-to-ambient thermal resistance (ºC/W)
PD = power dissipation in package
The junction-to-ambient thermal resistance is an industry standard value which provides a quick and easy
estimation of thermal perf ormance. However , the answer is only an estimate; test cases have demonstrated
that errors of a factor of two (in the quantity TJ-TA) are possible.
Output Low Voltage
IOL = 2.0 mA (CLKOUT)
IOL = 3.2 mA 3
IOL = 5.3 mA 4
IOL = 7.0 mA (TXD1/PA14, TXD2/PA12)
IOL = 8.9 mA (TS, TA, TEA, BI, BB, HRESET, SRESET)
VOL — 0.5 V
1
VIL(max) for the I2C interface is 0.8 V rather than the 1.5 V as specified in the I2C standard.
2
Input capacitance is periodically sampled.
3
A(0:31), TSIZ0/REG, TSIZ1, D(0:31), DP(0:3)/IRQ(3:6), RD/WR, BURST, RSV/IRQ2,
IP_B(0:1)/IWP(0:1)/VFLS(0:1), IP_B2/IOIS16_B/AT2, IP_B3/IWP2/VF2, IP_B4/LWP0/VF0, IP_B5/LWP1/VF1,
IP_B6/DSDI/AT0, IP_B7/PTR/AT3, RXD1 /PA15, RXD2/PA13, L1TXDB/PA11, L1RXDB/PA10, L1TXDA/PA9,
L1RXDA/PA8, TIN1/L1RCLKA/BRGO1/CLK1/PA7, BRGCLK1/TOUT1/CLK2/PA6,
TIN2/L1TCLKA/BRGO2/CLK3/PA5, TOUT2/CLK4/PA4, TIN3/BRGO3/CLK5/PA3,
BRGCLK2/L1RCLKB/TOUT3/CLK6/PA2, TIN4/BRGO4/CLK7/PA1, L1TCLKB/TOUT4/CLK8/PA0,
REJCT1/SPISEL/PB31, SPICLK/PB30, SPIMOSI/PB29, BRGO4/SPIMISO/PB28, BRGO1/I2CSDA/PB27,
BRGO2/I2CSCL/PB26, SMTXD1/PB25, SMRXD1/PB24, SMSYN1/SDACK1/PB23, SMSYN2/SDACK2/PB22,
SMTXD2/L1CLKOB/PB21, SMRXD2/L1CLKOA/PB20, L1ST1/RTS1/PB19, L1ST2/RTS2/PB18,
L1ST3/L1RQB/PB17, L1ST4/L1RQA/PB16, BRGO3/PB15, RSTRT1/PB14, L1ST1/RTS1/DREQ0/PC15,
L1ST2/RTS2/DREQ1/PC14, L1ST3/L1RQB/PC13, L1ST4/L1RQA/PC12, CTS1/PC11, TGATE1/CD1/PC10,
CTS2/PC9, TGATE2/CD2/PC8, CTS3/SDACK2/L1TSYNCB/PC7, CD3/L1RSYNCB/PC6,
CTS4/SDACK1/L1TSYNCA/PC5, CD4/L1RSYNCA/PC4, PD15/L1TSYNCA, PD14/L1RSYNCA, PD13/L1TSYNCB,
PD12/L1RSYNCB, PD11/RXD3, PD10/TXD3, PD9/RXD4, PD8/TXD4, PD5/REJECT2, PD6/RTS4, PD7/RTS3,
PD4/REJECT3, PD3, MII_MDC, MII_TX_ER, MII_EN, MII_MDIO, MII_TXD[0:3].
4
BDIP/GPL_B(5), BR, BG, FRZ/IRQ6, CS(0:5), CS(6)/CE(1)_B, CS(7)/CE(2)_B, WE0/BS_B0/IORD,
WE1/BS_B1/IOWR, WE2/BS_B2/PCOE, WE3/BS_B3/PCWE, BS_A(0:3), GPL_A0/GPL_B0, OE/GPL_A1/GPL_B1,
GPL_A(2:3)/GPL_B(2:3)/CS(2:3), UPWAITA/GPL_A4, UPWAITB/GPL_B4, GPL_A5, ALE_A, CE1_A, CE2_A,
ALE_B/DSCK/AT1, OP(0:1), OP2/MODCK1/STS, OP3/MODCK2/DSDO, BADDR(28:30).
Table 5. DC Electrical Specifications (continued)
Characteristic Symbol Min Max Unit