ATA5749/ATA5749C [DATASHEET]
9128J–RKE–07/15
20
3.5 DC voltage after XTAL
amplitude stable
V(XTO2) – V(XTO1)
XTO running 6, 7 VDC_XTO 40 mV C
3.6
Negative real part of
XTO impedance at
begin of start-up
This value is important for crystal
oscillator start-up behavior
C0 < 2.0pF,
8pF < CLOAD < 10pF
FXTAL = 13.000MHz
11.0MHz < FXTAL <14.8MHz
6, 7 RXTO12_START
–1,500
–1,300
–2,200 B
3.7 External capacitors
C4, C5
Recommended values for
proper start-up and low current
consumption
Quality NPO
CLOAD = (C4 + CXTO1)
(C5 + CXTO2) /
(C4 + C5 + CXTO1 + CXTO2)
CLoad_nom = 9pF (inc. PCB)
6, 7 C4
C5
–5% 15 +5% pF D
3.8 Pin capacitance
XTO1 and XTO2
The PCB capacitance of about
1pF has to be added 6, 7 CXTO1
CXTO2
–15%
–15%
2
2
+15%
+15% pF C
3.9 Crystal oscillator start-
up time
Time between EN = “High” and
XTO_RDY = “High”
C0 < 2.0pF, 4fF < CM < 15fF
C0 < 2.0pF, 2fF < CM < 15fF
RM < 170
11.0MHz < FXTAL < 14.8MHz
6, 7, 1 TXTO
0.20
0.32
0.3
0.5 ms B
3.10 Maximum shunt
capacitance C0 of XTAL
Required for stable operation of
XTO, CLoad > 7. 5pF 6, 7 C0_MAX 1.5 3.0 pF D
3.11 Oscillator frequency
XTO
433.92MHz and 315MHz other
frequencies 6, 7 fXTO 11.0
13.0000
14.8 MHz C
4Fractional-N-PLL
4.1 Frequency range of RF
frequency
S434_N315 = “LOW”
S434_N315 = “HIGH” 5 fRF
300
367
368
450 MHz A
4.2 Locking time of the PLL
Time between
XTO_RDY= “High” and Register
programmed till PLL is locked
fXTO = 13.0000MHz
other fXTO
1, 5 TPLL
98.46 µs B
4.3 PLL loop bandwidth Unity gain loop frequency of
synthesizer 5 fLoop_PLL 140 280 380 kHz B
4.4 In loop phase noise PLL 25kHz distance to carrier 5 LPLL –83 –76 dBc/Hz A
4.5 Out of loop phase noise
(VCO)
At 1MHz
At 36MHz 5Lat1M
Lat36M
–91
–122
–84
–115
dBc/Hz
dBc/Hz
A
C
4.6 FSK modulation
frequency
Duty cycle of the modulation
signal = 50%, (this corresponds
to 40kBit/s Manchester coding
and 80kBit/s NRZ coding)
2, 5 FMOD_FSK 040 kHz B
10. Electrical Characteristics (Continued)
VS = 1.9V to 3.6V Tamb = –40°C to +125°C, CLK_ON = “High”; DIV_CNTRL = “Low”, CLOAD_CLK = 10pF. fXTO = 13.0000MHz,
fCLK = 1.625MHz unless otherwise specified. If crystal parameters are important values correspond to a crystal with CM= 4.0fF,
C0= 1.5pF, CLOAD = 9pF and RM≤170. Typical values are given at VS= 3.0V and Tamb = 25°C
No. Parameters Test Conditions Pin Symbol Min. Typ. Max. Unit Type*
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note: (Pin Number) in brackets mean they are measured matched to 50 according to Figure 4-2 on page 8 with component
values and optimum load impedances according to Table 4-1 and Table 4-2 on page 9