Datasheet
71M6543F/71M6543G Data Sheet   
140    v2 
6.4.14  71M6543 VREF 
Table 102 shows the performance specifications for the 71M6543 ADC reference voltage (VREF).  
Table 102: 71M6543 VREF Performance Specifications 
Parameter  Condition  Min  Typ  Max  Unit 
VREF output voltage, 
VREF(22) 
T
A
 = 22 ºC 
1.193  1.195  1.197  V 
VREF output voltage, 
VREF(22) 
PLL_FAST=0 
  1.195    V 
VREF chop step, trimmed 
VREF(CHOP=01) − 
VREF(CHOP=10) 
-10    10  mV 
VREF power supply sensitivity 
 ΔVREF / ΔV3P3A 
V3P3A = 3.0 to 3.6 V  -1.5    1.5  mV/V 
VREF input impedance 
VREF_DIS = 1, 
VREF = 1.3 V to 1.7 V 
100      kΩ 
VREF output impedance 
VREF_CAL = 1, 
ILOAD = 10 µA, -10 µA 
    3.2  kΩ 
VNOM definition (see note 2) 
2)22(1)22()22()(
2
TCTTCTVREFTVNOM −+−+=
V 
If temperature characterization trim information is not available (71M6543F and 71M6543G) 
VNOM temperature 
coefficients: 
TC1 = 
TC2 = 
TRIMT⋅− 95.4275
TRIMT⋅−− 00028.0557.0
µV/°C 
µV/°C
2
VREF(T) deviation from 
VNOM(T) (see note 1): 
62
10
)(
)()(
6
TVNOM
TVNOMTVREF −
-40    +40  ppm/°C 
VREF aging 
±25 
ppm/ 
year 
Notes: 
1.  Guaranteed by design; not production tested. 
2.  This relationship describes the nominal behavior of VREF at different temperatures, as 
governed by a second order polynomial of 1
st
 and 2
nd
 order coefficients TC1 and TC2. 
3.  For the parameters in this table, unless otherwise specified, VREF_DIS  = 0, PLL_FAST=1 










