Rainbow Electronics MAX11008 - Manual (Page 42)

MAX11008
Dual RF LDMOS Bias Controller with
Nonvolatile Memory
42 ______________________________________________________________________________________
4) The resulting LUT pointer value is bound-limited to
ensure it fits within the corresponding LUT. Negative
pointer values are limited to zero, and pointer values
that extend beyond the range of the LUT are limited
to the last entry.
5) The final LUT pointer value is calculated by shifting
SOT to the left by 5 bits and then adding it to the
current LUT pointer value. If no linear interpolation
(INT = 00) is to be performed, the resulting LUT
pointer value is equal to the absolute EEPROM
address from which the LUT data is retrieved. If lin-
ear interpolation is to be performed (INT = 01, 10, or
11), the two LUT addresses that are closest to the
resulting LUT pointer value and their corresponding
data values are entered into the following equation
to calculate the interpolated data value that is used
in the V
GATE_ calculation:
where PTR is the calculated LUT pointer value with
fractional bits, ADD1 and ADD2 are the two LUT
addresses closest to the value of PTR, and DATA1 and
DATA2 are the LUT data values stored at ADD1 and
ADD2.
LUT Pointer Example 1 (No Interpolation)
POFF = 001000 (offset of +8).
INT = 00 (no interpolation/LUT pointer does not have
any fractional bits).
PSIZE = 00 (5-bit LUT pointer not including any frac-
tional bits).
TSIZE = 001 (LUT has 32 data locations).
SOT = 010 (LUT starts at EEPROM address 40 hex).
Interpolated Data DATA
PTR ADD
ADD ADD
x DATA DATA ( ) = +
−
−
⎛
⎝
⎜
⎞
⎠
⎟ − 1
1
2 1
2 1
DATA
BITS
BIT
NAME
RESET
STATE
FUNCTION
D [ 15:10] POFF 000000 POFF bits.
D[9:8] INT 00
Interpolation degree select bits.
See Table 5b.
D[7:6] PSIZE 00
LUT pointer size bit. See Table
5a.
D[5:3] TSIZE 000 LUT size bit. See Table 5c.
D[2:0] SOT 000
Start of table address bits. See
Table 5d.
Table 5. Temperature/APC LUT
Configuration Register
PSIZE LUT POINTER SIZE POFF OFFSET RANGE*
00
5-bit pointer (access up
to 32 data locations)
-32 to +31
01
6-bit pointer (access up
to 64 data locations)
-32 to +31
10
7-bit pointer (access up
to 128 data locations)
-64 to +62 (in steps of 2)
11
8-bit pointer (access up
to 256 data locations)
- 128 to + 124 ( i n step s of 4)
Table 5a. LUT Pointer Sizes and Offset
Ranges
INT
NUMBER OF FRACTIONAL BITS ADDED TO
LUT POINTER
00 0
01 1 ≥ 1:2 interpolation
10 2 ≥ 1:4 interpolation
11 3 ≥ 1:8 interpolation
Table 5b. Fractional Bits Added to LUT
Pointer for Linear Interpolation
*POFF is either a negative or positive number. When POFF is
negative its value is represented in two’s complement format.
TSIZE LUT SIZE
000 Unused
001 Table size of 32 data locations
010 Table size of 64 data locations
011 Table size of 96 data locations
100 Table size of 128 data locations
101 Table size of 160 data locations
110 Table size of 192 data locations
111 Unused
Table 5c. Selectable LUT Sizes
SOT STARTING ADDRESS IN EEPROM (HEX)
000 Unused
001 Unused
010 0x40
011 0x60
100 0x80
101 0xA0
110 0xC0
111 0xE0
Table 5d. Selectable LUT Starting
Addresses