N Register
Bit
N15
L
L
L
L
H
H
H
H
Table 3. VHF PDout Response
R Register Bits
R18
R17
L
L
L
H
H
L
H
H
L
L
L
H
H
L
H
H
VHF Phase Detector Response (Nominal)
Linear response, no low–gain region
Low–gain region, 5 ns wide
Low–gain region, 10 ns wide
Low–gain region, 15 ns wide
Linear response, no dead zone
Dead zone, 5 ns wide
Dead zone, 10 ns wide
Dead zone, 15 ns wide
NOTES:
1. L = Low Level, H = High Level.
2. See Figure 19.
LOW–PASS FILTER
OUTPUT VOLTAGE
LINEAR
RESPONSE
LOW
GAIN
REGION
NONLINEAR RESPONSES
PHASE ERROR
DEAD ZONE
OR
LOW–GAIN REGION
NOTES:
1. Output HF PDout always has a linear transfer characteristic. Therefore, for HF PDout, the Dead Zone = 0 ns.
2. Output VHF PDout has a response which is programmable via bits φdet1 (R18), φdet0 (R17), and Zone (N15).
See Table 3.
3. The gain in the “low–gain region” is reduced to 7% of the gain in the other region.
Figure 19. VHF PDout Transfer Characteristic
Table 4. Test Modes
R Register Bits
Pin Configurations
R21
R18
R17
Pin 12 — OUTPUT A
L
L
L
OUTPUT A, normal configuration
Pin 13 — OUTPUT B
OUTPUT B, normal configuration
L
L
H
fV, N counter output — HFin feeds the counter input
OUTPUT B, normal configuration
L
H
L
fV, N counter output — VHFin feeds the counter input OUTPUT B, normal configuration
L
H
H
OUTPUT A, normal configuration
fR, R counter output
H
X
X
OUTPUT A, normal configuration
OUTPUT B, normal configuration
NOTE: L = Low Level, H = High Level, X = Don’t Care.
MOTOROLA
MC145173
15