SA7025 Datasheet, PDF (7/22 Pages) NXP Semiconductors – Low-voltage 1GHz fractional-N synthesizer

Philips Semiconductors
1GHz low-voltage Fractional-N synthesizer
Product specification
SA7025
AC ELECTRICAL CHARACTERISTICS (continued)
SYMBOL
PARAMETER
TEST CONDITIONS
LIMITS
UNITS
MIN
TYP
MAX
t_SW
Pulse width; STROBE
A word, PR = ‘01’
A word, PR = ‘10’
1
f_VCO
@
(NM2
@
65)
)
t_W
ns
1
fVCO
@
[(NM2
@
65)
)
(NM3
)
1)
@
72]
)
tW
NOTES:
1. When a serial input “A” word is programmed, the main charge pumps on PHP and PHI are in the “speed up mode” as long as STROBE = H.
When this is not the case, the main charge pumps are in the “normal mode”.
2. The relative output current variation is defined thus:
DI_OUT
I_OUT
+
2
@
(I₂
|(I₂
*
)
I₁)
I₁)|
;
with
V₁
=
0.7V,
V₂
=
V_DDA
–
0.8V
(see
Figure
3).
3. F_RD is the value of the 3 bit fractional accumulator.
4. Monotonicity is guaranteed with C_N = 0 to 255.
5. Power supply current measured with V_DD = V_CCP = 3V, V_DDA = 5V, f_{RF IN} = 915.99MHz, XTAL at 21.36MHz, AUX at 85.92MHz (PA = ‘0’),
Main comp frequency = 240kHz, Auxiliary comp frequency = 120kHz, CN = 160, CL = 0, CK = 0. Internal registers NM1 = 52, NM2 = 0,
NM3 = 4, PR = ‘10’, SM = ‘00’, SA = ‘01’, NA = 179, NF = 5, FMOD = 8, NR = 89, PA = 0, IRN = IRA = IRF = 25µA, lock condition, normal
mode. Operational supply current = I_DDA + I_DD + I_CCP.
6. Specification condition: CN = 255
7. Specification conditions:
1) CN = 255; CL = 1, or
2) CN = 75; CL = 3
8. Typical output current | I_PHI | = –I_RN x CN x 2^(CL+1) x CK/32:
1) CN = 160; CL = 3; CK = 1, or
2) CN = 160; CL = 2; CK = 2, or
3) CN = 160; CL = 1; CK = 4, or
4) CN = 160; CL = 0; CK = 8
9. Any RFD, CL = 1 for speed-up pump. The integral pump is intended for switching only and the fractional compensation is not guaranteed.
10. Specification conditions: F_RD = 1 to 7; CL = 1.
11. Specification conditions:
1) F_RD = 1 to 7; CL = 1; CK = 2, or
2) F_RD = 1 to 7; CL = 2; CK = 1.
12. The matching is defined by the sum of the P and the N pump for a given output voltage.
13. Limited analog supply voltage range 4.5 to 5.5V.
14. For f_IN < 50MHz, low frequency operation requires DC-coupling and a minimum input slew rate of 32V/µs.
15. Guaranteed by design.
16. Close in noise for the charge pumps is tested on a sample basis in a typical application in order to eliminate parts outside the normal
distribution.
17. F_XTAL = 14.4MHz, V_XTAL = 500mV_P-P, comparison frequency = 200kHz, Loop bandwidth = 5kHz, Audio filter = 300Hz to 15kHz.
1996 Aug 6
7